Download Virtual Physical Science Lab Record Sheets

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Virtual Physical Science
Lab Record Sheets
Brian F. Woodfield
Heather J. McKnight
Steven Haderlie
Bradley D. Moser
Boston, Massachusetts
Upper Saddle River, New Jersey
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Copyright © by Pearson Education, Inc., publishing as Pearson Prentice Hall, Boston, Massachusetts 02116. All rights
reserved. Printed in the United States of America. This publication is protected by copyright, and permission should be
obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or
by any means, electronic, mechanical, photocopying, recording, or likewise. The publisher hereby grants permission to
reproduce the student worksheets, in part or in whole, for classroom use only, the number not to exceed the number of
students in each class. Notice of copyright must appear on all copies. For information regarding permission(s),
write to: Rights and Permissions Department, One Lake Street, Upper Saddle River, New Jersey 07458.
Pearson Prentice Hall™ is a trademark of Pearson Education, Inc.
Pearson® is a registered trademark of Pearson plc.
Prentice Hall® is a registered trademark of Pearson Education, Inc.
13-digit ISBN 978-0-13-362834-0
10-digit ISBN 0-13-362834-5
1 2 3 4 5 6 7
13 12 11 10 09
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Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Installing Virtual Physical Science . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Getting Started. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Lab 1:
Introduction to Scientific Inquiry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Lab 2:
Making Sense of Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Lab 3:
Investigation of Gas Pressure and Mass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Lab 4:
Pressure and Volume of a Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Lab 5:
Pressure and Temperature of a Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Lab 6:
Changes Between a Solid and a Liquid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Lab 7:
Changes Between a Liquid and a Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Lab 8:
Thomson and Smaller Parts of Atoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Lab 9:
Rutherford and the Nucleus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Lab 10: Elements and the Periodic Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Lab 11: Density of Solids and Liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Lab 12: Creating Chemical Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Lab 13: Names and Formulas of Ionic Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Lab 14: Describing Chemical Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Lab 15: Using Energy to Observe Chemical Changes . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Lab 16: Boiling Point Elevation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
© Pearson Education, Inc. All rights reserved.
Lab 17: Endothermic vs. Exothermic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Lab 18: Acid-Base Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Lab 19: Energy of a Chemical Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Lab 20: Investigating the Properties of Alpha and Beta Particles . . . . . . . . . . . . . . . . 52
Lab 21: Measuring Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Lab 22: Graphing Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Lab 23: Acceleration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Lab 24: Forces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Lab 25: Measuring Friction: A Sticky Topic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Lab 26: Acceleration and Friction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Contents
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Lab 27: Gravity and Free Fall Motion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Lab 28: Newton’s First Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Lab 29: Newton’s Second Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Lab 30: Newton’s Third Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Lab 31: Conservation of Momentum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Lab 32: Floating Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Lab 33: Density and Buoyancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Lab 34: The Work of the Egyptians. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Lab 35: Falling Elevator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Lab 36: Thermal Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Lab 37: Potential Energy to Kinetic Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Lab 38: Temperature and Volume of a Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Lab 39: Specific Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Lab 40: Blackbody Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Lab 41: Wave Properties of Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Lab 42: Particle Properties of Light. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Lab 43: Atomic Emission of Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Lab 45: Concave Mirror Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Lab 46: Convex Mirror Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Lab 47: Looking at Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Lab 48: Ohm’s Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Lab 49: Circuit Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Lab 50: Building Electrical Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Lab 51: Making Observations of Our Solar System . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Lab 52: Tracking the Phases of the Moon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Lab 53: Measuring the Orbital Speed of the Planets . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Lab 54: How Strong is Gravity? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Lab 55: Why Pluto is Not a Planet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
iv
Contents
© Pearson Education, Inc. All rights reserved.
Lab 44: Plane Mirror Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
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© Pearson Education, Inc. All rights reserved.
Overview
Welcome to Virtual Physical Science, a set of realistic and sophisticated
simulations covering topics in chemistry, physics, and planetary motion. In
these laboratories, students are put into a virtual environment where they are
free to make the choices and decisions that they would confront in an actual
laboratory setting and, in turn, experience the resulting consequences. These
laboratories include simulations of inorganic qualitative analysis, fundemental
experiments in quantum chemistry, gas properties, titrations, calorimetry,
mechanics and planetary motion, density, circuits, and optics. This overview
and the installations instructions are for the single version of Virtual Physical
Science v3.0.
After installing the Virtual Physical Science simulations, the software is
configured to access the laboratories either through the electronic workbook or
by clicking on the Physical Science Laboratory door. The electronic workbook is
designed to be used in conjunction with worksheets that are provided with the
software and will most likely be the principle method for gaining access to the
various laboratory simulations. However, students can also be given electronic
assignments through the Web Connectivity Option that they accept inside the
various laboratories and report their results back through the electronic lab
book. These types of assignments are accessed by entering through the Virtual
Physical Science door and providing a user name, password, and the URL
address for the Y Science server. Details on receiving and submitting electronic
assignments are given in the various laboratory user guides. It is strongly
suggested the user guides be reviewed before running the software. See the
Getting Started section for more information on using Virtual Physical Science
with the accompanying workbook. A brief description of the nine chemistry
and physics laboratories found in Virtual Physical Science is given below.
The mechanics laboratory provides students the flexibility to perform many
fundamental experiments to teach the basic concepts of Newton’s laws and
planetary motion that are easier to model in a simulated situation rather than a
real laboratory. The ability to control the frictions, forces, and physical
parameters of motion allows students the ability to easily use equipment that
can be found in most instructional laboratories and some equipment that would
be less readily available. Students are able to measure speeds and distances,
describe the motion of objects using graphs, interpret data, understand our
solar system, and gain a foundation for concepts in physics. These results can
then be used to validate Newton’s laws; demonstrate the interplay between
force and motion; calculate conservation of momentum; and study the
intricacies of the solar system under variable initial conditions and parameters.
A partial list of the experiments performed in the mechanics laboratory include
projectile motion in uniform or radial gravity, ramp motion in uniform or radial
gravity, the collision of multiple balls with elastic or inelastic collisions, a falling
rod, and the motion of the planets and their moons in the solar system viewed
from various perspectives. The difficulty level of these experiments ranges from
basic to sophisticated, depending on the level of the class and the purpose for
performing the experiments.
The features of the inorganic simulation include 26 cations that can be
added to test tubes in any combination, 11 reagents that can be added to the
test tubes in any sequence and any number of times, necessary laboratory
manipulations, a lab book for recording results and observations, and a
Overview
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vi
Overview
© Pearson Education, Inc. All rights reserved.
stockroom for creating test tubes with known mixtures, generating practice
unknowns, or retrieving instructor assigned unknowns. The simulation uses
over 2,500 actual pictures to show the results of reactions and over 220 videos
to show the different flame tests. With 26 cations that can be combined in any
order or combination and 11 reagents that can be added in any order, there are
in excess of 1016 possible outcomes for these simulations.
The purpose of the quantum laboratory is to allow students to explore and
better understand the foundational experiments that led to the development of
atomic theory and an understanding of the atom. Because of the very
sophisticated nature of most of these experiments, the quantum laboratory is
the most “virtual” of the Virtual Physical Science laboratory simulations. In
general, the laboratory consists of an optics table where a source, sample,
modifier, and detector combination can be placed to perform different
experiments. These devices are located in the stockroom and can be taken out
of the stockroom and placed in various locations on the optics table. The
emphasis here is to teach students to probe a sample (e.g., a gas, metal foil, twoslit screen, etc.) with a source (e.g., a laser, electron gun, alpha-particle source,
etc.) and detect the outcome with a specific detector (e.g., a phosphor screen,
spectrometer, etc.). Heat, electric fields, or magnetic fields can also be applied
to modify an aspect of the experiment. As in all Virtual Physical Science
laboratories, the focus is to allow students the ability to explore and discover, in
a safe and level-appropriate setting, the concepts that are important in the
various areas of chemistry.
The gas experiments included in the Virtual Physical Science simulated
laboratory allow students to explore and better understand the behavior of
ideal gases, real gases, and van der Waals gases (a model real gas). The gases
laboratory contains four experiments each of which includes the four variables
used to describe a gas: pressure (P), temperature (T), volume (V), and the
number of moles (n). The four experiments differ by allowing one of these
variables to be the dependent variable while the others are independent.
The four experiments include (1) V as a function of P, T, and n using a balloon to
reflect the volume changes; (2) P as a function of V, T, and n using a motordriven piston; (3) T as a function of P, V, and n again using a motor-driven piston;
and (4) V as a function of P, T, and n but this time using a frictionless, massless
piston to reflect volume changes and using weights to apply pressure. The
gases that can be used in these experiments include an ideal gas; a van der
Waals gas with parameters that can be changed to represent any real gas; real
gases including N2, CO2, CH4, H2O, NH3, and He; and eight ideal gases with
different molecular weights that can be added to the experiments to form gas
mixtures.
The virtual titration laboratory allows students to perform precise,
quantitative titrations involving acid-base and electrochemical reactions. The
available laboratory equipment consists of a 50 mL buret, 5, 10, and 25 mL
pipets, graduated cylinders, beakers, a stir plate, a set of 8 acid-base indicators,
a pH meter/voltmeter, a conductivity meter, and an analytical balance for
weighing out solids. Acid–base titrations can be performed on any
combination of mono-, di-, and tri-protic acids and mono-, di-, and tri-basic
bases. The pH of these titrations can be monitored using a pH meter, an
indicator, and a conductivity meter as a function of volume, and this data can
be saved to an electronic lab book for later analysis. A smaller set of
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potentiometric titrations can also be performed. Systematic and random errors
in the mass and volume measurements have been included in the simulation
by introducing buoyancy errors in the mass weighings, volumetric errors in the
glassware, and characteristic systematic and random errors in the pH/
voltmeter and conductivity meter output. These errors can be ignored, which
will produce results and errors typically found in high school or freshman-level
laboratory work, or the buoyancy and volumetric errors can be measured and
included in the calculations to produce results better than 0.1% in accuracy and
reproducibility.
The calorimetry laboratory provides students with three different
calorimeters that allow them to measure various thermodynamic processes
including heats of combustion, heats of solution, heats of reaction, the heat
capacity, and the heat of fusion of ice. The calorimeters provided in the
simulations are a classic “coffee cup” calorimeter, a dewar flask (a better
version of a coffee cup), and a bomb calorimeter. The calorimetric method used
in each calorimeter is based on measuring the temperature change associated
with the different thermodynamic processes. Students can choose from a wide
selection of organic materials to measure the heats of combustion; salts to
measure the heats of solution; acids, bases, oxidants, and reductants for heats
of reaction; metals and alloys for heat capacity measurements; and ice for a
melting process. Temperature versus time data can be graphed during the
measurements and saved to the electronic lab book for later analysis.
Systematic and random errors in the mass and volume measurements have
been included in the simulation by introducing buoyancy errors in the mass
weighings, volumetric errors in the glassware, and characteristic systematic
and random errors in the thermometer measurements.
The density laboratory allows students the ability to measure the mass and
volume of a large set of liquids and solids, which, in turn, will allow them to
explore the fundamental concepts governing density and buoyancy. The
laboratory has a set of graduated cylinders that can be filled with various
liquids such as water, corn syrup, mercury, jet fuel, tar, plus many others. These
cylinders can be filled with one or two liquids to study miscibility or the
relative density of the liquids. The laboratory also contains a large selection of
solids that can be dropped into these cylinders, and the students can then
observe whether the solids float or sink in the selected liquids. The density of
the solids can be calculated by measuring the mass of the solids and the volume
of liquid displaced in the cylinders after the solids have been dropped into the
liquid. The density of the liquids can be determined by measuring the mass and
volume of the liquid.
The circuit laboratory gives students the freedom to discover and learn the
principles associated with simple electrical circuits involving resistors,
capacitors, and inductors. The laboratory allows students to build circuits using
either a breadboard or schematic representation. Using the breadboard students
will connect components as they would in an ordinary circuit laboratory by
adding resistors, light bulbs, capacitors, or inductors of any combination and a
battery or function generator. When using the schematic the students can
“draw” a circuit schematic on paper as they would to plan a circuit. The
breadboard and schematic are linked together so they automatically populate
when the other one is changed. Using the digital multimeter and oscilloscope
this type is to justify para
Installing Virtual Physical Science
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students can then analyze their circuits and learn principles like Ohm’s Law, the
power-voltage relationship, AC/DC sources, and much more.
The optics laboratory gives students the freedom to discover and learn the
principles associated with simple optical experiments involving light sources,
objects, mirrors, lenses, prisms, and filters. The laboratory allows students to set
up optical experiments on a standard optics table by placing components on the
table and moving the viewing detector or virtual eye to different locations to
observe the resulting image characteristics. When setting up experiments with
mirrors and lenses in different combinations, students can analyze their layouts
to test image characteristics depending on object locations and verify the
lensmaker equations. Principles of light addition and subtraction can be
studied with filters and prism light recombination. Snell’s Law and the law of
reflection can also be investigated.
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viii Installing Virtual Physical Science
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System Requirements
Minimum system requirements are as follows:
PC
Pentium 1 GHz (Pentium III or better recommended)
256 Mb RAM (512+ Mb Recommended)
CD-ROM drive (for installation only)
1 Gb of free disk space
Display capable of and set to millions of colors (24 bit color)
Recommended minimum resolution 1024 x 768
Windows 2000 Professional or Windows XP
QuickTime 6.x/7.x
Macintosh
PowerPC (G3 or better recommended)
256 Mb RAM (512+ Mb recommended)
CD-ROM drive (for installation only)
1 Gb of free disk space
Display capable of and set to millions of colors (24-bit color)
Recommended minimum resolution 1024 x 768
OS X (any version)
QuickTime 6.x/7.x
Note: The above requirements are the recommended minimum hardware and
system software requirements for reasonable execution speeds and
reliability. However, it should be noted that the software has been
successfully installed and used on computers with significantly lower
capabilities than the recommendations given above with corresponding
reductions in execution speed and media access time.
Installing Virtual Physical Science
© Pearson Education, Inc. All rights reserved.
Locate and run the program “Setup VPS” on the CD-ROM drive then follow
the prompts. There is only one install option available for the single user
version, which installs the complete software package to the hard drive. The
CD is not needed to run the program after performing the installation.
Important Installation Notes and Issues
1. The graphics used in the simulations require the monitor to be set to 24-bit
true color (millions of colors). Lower color resolutions can be used, but the
graphics will not be as sharp.
2. When installing Virtual Physical Science, you must be logged in as an
Administrative User in order for all files and folders to be installed
correctly and to have correctly configured file permissions; otherwise,
unpredictable results such as hard crashes and other errors can occur
during installation and running Virtual Physical Science.
3. The Inorganic simulation will not run on some Macintosh Macbooks using
an Intel-based processor. This is a known issue affecting all Adobe
(formerly Macromedia) Director products, however there is some
disagreement whether the fault is in Director or OS X. This problem does
System Requirements
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not appear on Macbook Pros and only on some regular Macbooks. The
current solution to this issue is to install the software on Windows running
in a virtual machine such as VMware or Parallels.
4. Occasionally when installing on the OS X operating system, the system
fails to copy over the VCL icon for aliases created on the desktop. There is
no known cause for this. Aliases with the correct icon can be created
manually inside the installation directory or by copying a VCL icon on to
an already existing alias.
5. When installing on the OS X operating system v10.4 (or Tiger), selecting the
option to place an alias on the dock causes the dock to be reset to its initial
installed state and any dock customization is lost.
6. In the directory where Virtual Physical Science is installed, the user must
always have read/write privileges to that directory and all directories
underneath. This is the default state for all Administrative Users (both Mac
and PC), and this condition has been set by the installer for Standard Users in
OS X as well. However, if users will be logged in as Restricted Users in
Windows (such as in a computer lab), then the privileges for the Virtual
Physical Science directory must be set manually to “Full Access” for Everyone.
The installer attempts to set these permissions for Windows installations, but
for unknown reasons it is not always successful. In addition, if the system
crashes hard while running Virtual Physical Science (either on Windows or OS
X), these permissions may have to be reset to read/write for everyone.
8. When installing Virtual Physical Science on to the OS X operating system, the
user must have read/write permission for the folder into which Virtual
Physical Science will be installed. In the vast majority of cases, Virtual Physical
Science will be installed into the Applications folder, but in order for this to
be successful the user must be an Administrative User. In some cases,
however, the permissions for the Applications folder have been modified by
other software installed on the machine, which will prevent Virtual Physical
Science from being installed in the Applications folder. These permissions
can be reset back to their default state using the Repair Disk Permissions
function in the Disk Utility program located in the Applications folder.
9. QuickTime 6.0 or later is required for the software to run properly.
The most recent version of QuickTime can be obtained at
http://www.apple.com/quicktime/.
10. For unknown reasons, on some machines the QuickTime videos will not
play properly if the system QuickTime settings are in their default state.
This can be corrected by changing the Video Settings in QuickTime to
Normal Mode.
x
Installing Virtual Physical Science
© Pearson Education, Inc. All rights reserved.
7. The installer does not allow installation and other directory paths to be
typed in directly, but all installation paths must be identified or selected by
browsing to the desired location. When installing on the OS X operating
system, browsing to a folder using aliases occasionally causes the installer
to spontaneously shutdown. Consequently, it is recommend that aliases be
avoided when browsing. There is no known cause for this.
sx07CAGr8_VPhyLab_FM.fm Page xi Friday, August 17, 2007 6:54 AM
Getting Started
© Pearson Education, Inc. All rights reserved.
After Virtual Physical Science has been successfully installed, the VPS icon used
to launch the program will be located on the desktop, in a Program Group on
PC machines, and on the Dock for Macintosh machines. Clicking on the VPS
icon will start the simulation where you will be brought to a hallway
containing two doors and a workbook sitting on a table (see Figure 1). Clicking
on the electronic workbook opens and zooms into the workbook pages (see
Figure 2) where you can select preset assignments that correspond to the
assignments in the student workbook. The Previous and Next buttons are used
to page through the set of assignments, and the different assignments can also
be accessed by clicking on the section titles located on the left page of the
workbook. Clicking on the Enter Laboratory button will allow you to enter the
physical science laboratory (see below), and the Exit button is used to return to
the hallway.
From the hallway, students can also enter the physical science laboratory by
clicking on the Physical Science Laboratory door and entering as a guest. Once in
the laboratory, students will find nine laboratory benches that represent the
nine different physical science laboratories. By mousing over each of these
laboratory benches students can display the name of the selected laboratory. To
access a specific laboratory, click on the appropriate laboratory bench. While in
the physical science laboratory, the full functionality of the simulation is
available, and students are free to explore and perform experiments as dictated
by their instructors or by their own curiosity. The Exit signs in the physical
science laboratory are used to return to the hallway.
Detailed instructions on how to use each of the nine laboratory simulations
can be found in the User Guides located in the Virtual Physical Science CD.
These same user guides can also be accessed inside each laboratory by clicking
on the Pull-Down TV and clicking on the Help button. For those students who
will be given electronic assignments from their instructor through the web,
they should enter the laboratory through the door and provide their user name,
password, and the URL address of the Y Science server at the card reader.
Details on accessing Virtual Physical Science can be found in the Accessing VPS
user guide found on the CD.
Getting Started
xi
sx07CAGr8_VPhyLab_01.fm Page 1 Thursday, July 19, 2007 8:43 AM
Name ___________________________
Date ___________________
Class ____________
Lab 1: Introduction to Scientific Inquiry
Introduction to Scientific
Inquiry
Purpose
To show how the processes of scientific inquiry can help you learn about the
natural world
Background
Scientific inquiry is a way of learning about the natural world by gathering
information and then trying to make sense of it. Scientific inquiry does not
always occur in the same way, but certain steps are often involved. Some steps
that scientists often use in their investigations are posing questions, developing
hypotheses, designing experiments, collecting and interpreting data, drawing
conclusions, and communicating ideas and results.
Skills Focus
Posing questions, developing hypotheses, designing an experiment, collecting
and interpreting data, interpreting a graph, predicting, drawing conclusions,
communicating
Introduction
© Pearson Education, Inc. All rights reserved.
1. Posing Questions Have you ever observed how a gas in a balloon acts
when heated? What did you see? What questions could you ask about how
changing temperature affects the gas in a balloon? (Remember, the questions
you ask should be questions that can be answered by making observations.)
__________________________________________________________________
2. Developing Hypotheses Scientific inquiry moves forward when ideas can
be tested. Your first step is to develop a hypothesis. A hypothesis is a
possible answer to a scientific question or an explanation for a set of
observations. Your hypothesis is not a fact. It must be tested. Your
observations may support your hypothesis or they may not. If they do not
support your hypothesis, you have not wasted your time. You have learned
that your hypothesis is not correct and that you must explore further. Write
a hypothesis about the volume of a balloon when the temperature of the gas
in a balloon is changed.
__________________________________________________________________
Introduction to Scientific Inquiry
1
sx07CAGr8_VPhyLab_01.fm Page 2 Thursday, July 19, 2007 8:43 AM
Introduction to Scientific
Inquiry
Name ___________________________
Date ___________________
Class ____________
3. Designing an Experiment Scientists test hypotheses by designing
controlled experiments. A controlled experiment is one in which all but one
of the variables remain the same. The variable that you change in your
experiment is the controlled parameter. The variable that changes because of
what you do is the variable parameter.
a. How would you design a controlled experiment to test your hypothesis
about the balloon?
_______________________________________________________________
b. What is the controlled parameter in your experiment?
_______________________________________________________________
c. What is the variable parameter in your experiment?
_______________________________________________________________
4. Collecting and Interpreting Data Observations can be qualitative or
quantitative. Qualitative observations are descriptions, such as notes you
might make in a journal or notebook. Quantitative observations are
measurements that are usually recorded in tables with their units. Scientists
make it easier to share data by using the same system of measurement with
standard units of measure. In your experiment the unit for volume is cubic
centimeters (cm3). The unit for temperature is degrees Celsius (°C).
Procedure
1. Start Virtual Physical Science and select Introduction to Scientific Inquiry from
the list of assignments. The lab will open in the Gases laboratory.
3. Observe the current volume and temperature of the gas and record them in
the table. Now, click on the 1 in the temperature window. The digit should
turn green. Type 2, so that the temperature is now 200°C. Record the new
volume and temperature in the table. Repeat this step again but type 3 in the
temperature window. Again, record your data. Continue to increase the
temperature by 100°C each time and record your data until you reach 700°C.
Temperature (°C)
2
Introduction to Scientific Inquiry
Volume (cm3)
© Pearson Education, Inc. All rights reserved.
2. Note that the balloon in the chamber is filled with a gas at a temperature of
100°C and a pressure of 101.3 kPa. The volume of the gas is 1531 cm 3.
sx07CAGr8_VPhyLab_01.fm Page 3 Thursday, July 19, 2007 8:43 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
Introduction to Scientific
Inquiry
1. Communicating The data you placed in the data table is quantitative data.
Qualitative data would be your written observations about what happened
in the experiment. Write a short summary of what you observed.
__________________________________________________________________
2. Making a Graph You can plot the information in the data table on a graph.
Plot the controlled parameter on the horizontal axis and the variable
parameter on the vertical axis.
© Pearson Education, Inc. All rights reserved.
a. What measurement (with its units) is plotted on the horizontal axis
(x-axis)?
_______________________________________________________________
b. What measurement (with its units) is plotted on the vertical axis
(y-axis)?
_______________________________________________________________
c. At 450°C, what is the approximate volume?
_______________________________________________________________
d. Predicting What will be the approximate volume when the temperature
is 1000°C?
_______________________________________________________________
Introduction to Scientific Inquiry
3
sx07CAGr8_VPhyLab_01.fm Page 4 Thursday, July 19, 2007 8:43 AM
Introduction to Scientific
Inquiry
Name ___________________________
Date ___________________
Class ____________
3. Drawing Conclusions After scientists interpret their data, they draw
conclusions about their hypothesis. A conclusion states whether the data
support the hypothesis. Review your hypothesis. Look at the information in
the table and the graph. What conclusion can you make about your
hypothesis?
__________________________________________________________________
4. Communicating An important part of scientific inquiry is communicating.
Communicating is sharing ideas and conclusions with others through
writing and speaking. It is also sharing the process you used in your inquiry.
Assume you are a television reporter and are assigned to do a story about the
experiment you just completed. Write a short summary for your television
audience describing the process of scientific inquiry. Use the procedure and
results of this experiment as an example.
© Pearson Education, Inc. All rights reserved.
4
Introduction to Scientific Inquiry
sx07CAGr8_VPhyLab_02.fm Page 5 Wednesday, August 8, 2007 2:09 PM
Name ___________________________
Date ___________________
Class ____________
Lab 2: Making Sense of Density
Purpose
To discover whether different metals have different densities
Background
A kilogram of gold takes up much less space than a kilogram of feathers
because gold has a much higher density than feathers. Density is the amount of
mass of a substance in a given volume. Often, density is expressed as the
number of grams in one milliliter (g/mL). In order to calculate the density of a
substance, you need to know both the mass and the volume. The mathematical
formula for density is shown below.
Mass
Density --------------------Volume
or
dm
---V
Making Sense of Density
The formula shows that you find density by dividing the mass by the volume.
You can calculate the volume of a spherical object (ball) using this formula:
3
Volume of a ball 4--- r , where “r” is the radius
3
This will give you the volume of the solid balls from just knowing their radii.
It is also possible to calculate the volume by measuring the amount of fluid
displaced by the object in a known volume. 1 mL is equal to 1 cm 3. The unit for
density in this lab will be g/mL.
Skills Focus
Calculating, relating cause and effect, drawing conclusions
Procedure
© Pearson Education, Inc. All rights reserved.
1. Start Virtual Physical Science and select Making Sense of Density from the list
of assignments. The lab will open in the Density laboratory.
2. Find the gold ball on the lab wall. Pick up the ball and drag it to the
spotlight on the balance. Record the mass in the table.
3. The approximate radius of the gold ball is 1.6 cm. Using this information
and the formulas given earlier, calculate the volume of the ball and the
density of the gold. Record your answers in the table.
4. Repeat the experiment for aluminum (Al). You can also calculate the volume
of the ball by measuring the volume of water displaced by the object. On the
laboratory bench, you can see a 250 mL graduated cylinder filled with water.
Click on the cylinder to see a zoomed-in view of the level of the water.
Record the initial volume of the water in the table.
Making Sense of Density
5
sx07CAGr8_VPhyLab_02.fm Page 6 Wednesday, August 8, 2007 2:09 PM
Name ___________________________
Date ___________________
Class ____________
5. Drag the aluminum ball to the top of the cylinder and drop it in the cylinder
of water. Click the green Release button to let the ball fall into the water.
Look at the close-up view window to note the new volume of the water.
Record the final volume in the table. The volume of your aluminum ball
will be the difference of the final volume of the water with the ball and the
initial volume of just the water. Record the calculated volume of the ball in
the table.
Ball
Mass of Ball
(g)
Volume of
Water (mL)
Volume of
Water and
Ball (mL)
Volume of
Ball
Density
(g/mL)
Au
Making Sense of Density
Al
Analyze and Conclude
1. Applying Concepts If both of the objects were approximately the same
size, or volume, why did they have such different masses?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
3. Drawing Conclusions Aluminum and its alloys are the primary metals
used in the construction of airplanes. Does this make sense given its
density? Why?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
6
Making Sense of Density
© Pearson Education, Inc. All rights reserved.
2. Predicting Look through all the different options of balls. Which do you
think is the most dense and which would be the least dense? How could you
actually determine that?
__________________________________________________________________
sx07CAGr8_VPhyLab_03.fm Page 7 Thursday, July 19, 2007 8:44 AM
Name ___________________________
Date ___________________
Class ____________
Lab 3: Investigation of Gas Pressure
and Mass
Purpose
To determine the relationship between the internal pressure of a gas and an
applied external pressure
Background
An understanding of pressure is an important part of your understanding of
the behavior of gases. Pressure is defined as force per unit area. The pressure a
gas exerts is determined by temperature, external pressure, volume, and the
number of particles of gas present. This experiment will help you become more
familiar with pressure and how it is measured.
Skills Focus
Observing, calculating, predicting
Procedure
1. Start Virtual Physical Science and select Investigation of Gas Pressure and Mass
from the list of assignments. The lab will open in the Gases laboratory. Note
that in this experiment the internal pressure of the gas is the sum of the
pressure exerted by the gas and the pressure of any mass added to the
piston. If no mass is added to the piston, the internal pressure is equal to the
external pressure.
Investigation of Gas
Pressure and Mass
2. Click the green Piston button to move the piston onto the cylinder. Record
the mass in tons, the external pressure (in pounds per square inch, or psi)
and the internal pressure (in psi) in the table. (1 psi = 6.89 kPa)
© Pearson Education, Inc. All rights reserved.
3. Click on the tenths digit for the mass (the .0) on the Force Controller and enter
a 5. This will add 0.5 ton of mass to the piston. Record the mass, external
pressure (in psi) and internal pressure (in psi) in the table.
Mass
(tons)
External
Pressure
(psi)
Internal
Pressure
From
Meter (psi)
Calculated
Internal
Pressure
(psi)
Investigation of Gas Pressure and Mass
7
sx07CAGr8_VPhyLab_03.fm Page 8 Thursday, July 19, 2007 8:44 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
1. Calculating You can calculate the pressure exerted by 0.5 ton and
compare it with the pressure obtained in the experiment. To do this, you
need to convert the mass in tons to pounds. Then find the area of the piston
in square inches. With the mass in pounds and the area in square inches, you
can calculate the pounds pressing on each square inch (psi). First, convert
tons to pounds. One ton is 2000 pounds. How many pounds is 0.5 ton?
__________________________________________________________________
2
2. To calculate the area of the circular piston use the equation A r , where
A is the area, is 3.14 and r is the radius. The diameter of the piston is 15 cm.
Recall that the diameter of a circle is twice the radius. What is the radius of
the piston (in cm)?
__________________________________________________________________
3. To calculate pressure in pounds per square inch, the radius of the piston
must be changed from centimeters to inches. 1 inch = 2.54 cm, so the radius
of the piston in inches is calculated like this:
7.5 cm
----------------------------- 2.95 in
2.54 cm/in
2
4. The pressure exerted on the piston by the added mass in pounds per square
inch (psi) can be determined by dividing the mass in pounds (answer to
Question 1) by the area in square inches (answer to Question 3). What is the
pressure exerted by the added mass in psi?
__________________________________________________________________
5. The internal pressure of the gas is the sum of the external pressure and the
pressure exerted by the added mass. This is the sum of the external pressure
recorded in the table and the answer to Question 4. What is the calculated
internal pressure? Record your answer in the table. Compare your
calculated answer to the internal pressure meter answer. How do they
compare?
__________________________________________________________________
__________________________________________________________________
8
Investigation of Gas Pressure and Mass
© Pearson Education, Inc. All rights reserved.
Investigation of Gas
Pressure and Mass
Now use the equation A r to calculate the area of the piston in square
inches (in2).
__________________________________________________________________
sx07CAGr8_VPhyLab_03.fm Page 9 Thursday, July 19, 2007 8:44 AM
Name ___________________________
Date ___________________
Class ____________
6. Applying Concepts A bike tire is usually inflated to 40 psi as measured on a
tire gauge. This measurement represents the difference between the internal
pressure pushing on one end of the gauge and the air pressure pushing on the
other end of the gauge. To obtain the internal pressure, add the air pressure
(14.7 psi) to the gauge pressure (40 psi). The internal pressure is 54.7 psi. How
does the pressure calculated in 5 compare to the pressure in a bike tire?
__________________________________________________________________
__________________________________________________________________
7. a. Calculate the internal pressure (in psi) when 2.5 tons (the mass of a small
car) is placed on the piston. (Repeat Questions 1–5 using 2.5 tons instead
of 0.5 ton.)
_______________________________________________________________
b. How does your calculated answer compare to the internal pressure
meter when you add 2.5 tons of mass? Record your data in the table.
_______________________________________________________________
c. The gauge pressure for a tire on a passenger car is usually 32 psi.
Calculate the internal pressure for a car tire and compare it to your
answer for 7a.
_______________________________________________________________
_______________________________________________________________
© Pearson Education, Inc. All rights reserved.
Investigation of Gas
Pressure and Mass
Investigation of Gas Pressure and Mass
9
sx07CAGr8_VPhyLab_04.fm Page 10 Thursday, July 19, 2007 8:45 AM
Name ___________________________
Date ___________________
Class ____________
Lab 4: Pressure and Volume of a Gas
Purpose
To discover how changing the pressure on a gas-filled balloon affects the
volume of the balloon
Background
Robert Boyle, a philosopher and theologian, studied the properties of gases in
the 17th century. He noticed that gases behave like springs. When compressed
or expanded, gases tend to ‘spring’ back to their original volume. Boyle studied
the relationship between the pressure and volume of a gas and summarized his
results in what has become known as Boyle’s Law. You can make observations
similar to those of Robert Boyle by changing the pressure of a gas and
observing what happens to its volume.
Skills Focus
Graphing, predicting, interpreting data, controlling variables, drawing
conclusions
Procedure
1. Start Virtual Physical Science and select Pressure and Volume of a Gas from the
list of assignments. The lab will open in the Gases laboratory. Note that the
balloon in the chamber is filled with a gas at a temperature of 25 °C. The
pressure of the gas is 100 kPa. The volume of the balloon is 7436 cm 3.
3. Observe the beginning pressure and volume of the gas and record them in
the table. Now, click on the 1 in the pressure window. The digit should turn
green. Type 2 so that the pressure becomes 200 kPa. Record the new pressure
and volume in the table. Repeat this step again but set the pressure to
300 kPa. Again, record your data. Continue to increase the pressure by
100 kPa each time and record your data until you reach 700 kPa.
Pressure and Volume
of a Gas
Pressure (kPa)
10
Pressure and Volume of a Gas
Volume (cm3)
© Pearson Education, Inc. All rights reserved.
2. Predicting You are going to increase the pressure on the balloon. What
will happen to the volume of the balloon? Record your prediction.
__________________________________________________________________
sx07CAGr8_VPhyLab_04.fm Page 11 Thursday, July 19, 2007 8:45 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
1. Graphing Make a line graph of the data in the table. Show pressure in kPa
on the horizontal axis and volume in cm3 on the vertical axis.
2. Drawing Conclusions Did your results support your prediction? Explain.
__________________________________________________________________
__________________________________________________________________
3. Interpreting Graphs Is the relationship between pressure and volume
linear or nonlinear?
__________________________________________________________________
Decrease the pressure on the balloon to check your prediction. Pull down on
the lever on the pressure controller until the tens digit turns blue and hold it.
This causes the pressure to decrease. Observe the balloon volume as the
pressure decreases.
Pressure and Volume
of a Gas
© Pearson Education, Inc. All rights reserved.
4. Predicting How would the volume of the gas be affected if the pressure
were decreased?
__________________________________________________________________
Pressure and Volume of a Gas
11
sx07CAGr8_VPhyLab_05.fm Page 12 Thursday, July 19, 2007 8:46 AM
Name ___________________________
Date ___________________
Class ____________
Pressure and Temperature
of a Gas
Lab 5: Pressure and Temperature of a Gas
Purpose
To explore how changing the temperature of a fixed volume of gas affects the
pressure of the gas
Background
The temperature of a gas is related to the motion of the particles of a gas. As
temperature increases, the gas molecules move faster. What effect does the
motion of gas molecules have on the pressure exerted by the gas? By changing
the temperature of the gas you will change the motion of the particles and can
observe what happens to the pressure.
Skills Focus
Graphing, predicting, interpreting data, controlling variables, drawing
conclusions
Procedure
1. Start Virtual Physical Science and select Pressure and Temperature of a Gas from
the list of assignments. The lab will open in the Gases laboratory. Note that
the chamber is filled with a gas at a temperature of 100°C. The pressure of
the gas is 310.3 kPa. Its volume is 1000 cm3.
3. Record the beginning temperature and pressure of the gas in the table. Click
on the 1 in the temperature window. The digit should turn green. Type 2 so
that the temperature is 200°C. Record the new pressure and temperature in
the table. Repeat this step again but set the temperature to 300°C. Again,
record your data. Continue to increase the temperature by 100°C each time
and record your data until you reach 700°C.
Temperature (°C)
12
Pressure and Temperature of a Gas
Pressure (kPa)
© Pearson Education, Inc. All rights reserved.
2. Predicting You are going to increase the temperature of the gas in the
chamber. What effect will the change in temperature have on the pressure?
Record your prediction.
__________________________________________________________________
sx07CAGr8_VPhyLab_05.fm Page 13 Wednesday, August 8, 2007 2:11 PM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
Pressure and Temperature
of a Gas
1. Graphing Make a line graph of the data obtained in Step 3. Show
temperature in °C on the horizontal axis and pressure in kPa on the
vertical axis.
2. Drawing Conclusions Did your results support your prediction? Explain.
__________________________________________________________________
3. Interpreting Graphs Is the relationship between temperature and pressure
linear or nonlinear?
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
4. Predicting How would the pressure of the gas change if the temperature
were decreased?
__________________________________________________________________
To check your prediction, decrease the temperature in the container by
pulling down on the lever in the temperature controller until the tens digit
turns blue and holding the lever. Observe the pressure as the temperature
decreases.
Pressure and Temperature of a Gas
13
sx07CAGr8_VPhyLab_06.fm Page 14 Wednesday, August 8, 2007 2:18 PM
Name ___________________________
Date ___________________
Class ____________
Lab 6: Changes Between a Solid
and a Liquid
Purpose
To determine how temperature changes as ice is heated and becomes liquid
water
Background
Changes Between a Solid
and a Liquid
Depending on the temperature, most substances can exist as both a solid and a
liquid. A substance in its liquid state has more thermal energy than it has in its
solid state. The temperature at which a substance changes from a solid to a
liquid is the melting point of the substance. The melting point is a characteristic
property of a substance. Chemists often use the melting point to help identify
or classify a substance.
Skills Focus
Graphing, interpreting graphs, applying concepts, drawing conclusions
Procedure
2. Observe the temperature of the ice/water mixture graphed in the plot
window as a function of time until the blue graph line reaches four (4)
minutes. Click Save on the Plot window. A blue link will appear in the lab
book. Click on the link in the lab book to display the graph for the time
0–4 minutes.
14
Changes Between a Solid and a Liquid
© Pearson Education, Inc. All rights reserved.
1. Start Virtual Physical Science and select Changes Between a Solid and a Liquid
from the list of assignments. The lab opens in the Calorimetry laboratory. A
coffee cup calorimeter filled with an ice/water mixture is on the lab bench.
The ice has just been placed in the cup, so the temperature of the water is
initially lowering as the ice cools the water down. The ice water is being
stirred and as time passes the ice will begin to melt as the cup heats up. You
will analyze the graph of the temperature to determine when the melting
occurs. Click the clock on the wall labeled Accelerate to accelerate the
laboratory time. Click on the lab book to open it. Click the Plot window to
bring it to the front.
sx07CAGr8_VPhyLab_06.fm Page 15 Wednesday, August 8, 2007 2:18 PM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
1. Graphing On the grid below, make a sketch of what you observed of the
temperature of the water as it changed with time. Label the axes. Label the
part of the line where the water is a mixture of ice and liquid water. Label
the part of the line where the water is all liquid.
Changes Between a Solid
and a Liquid
2. a. Interpreting Graphs What is the state or states of the water in the
calorimeter at 0°C?
_______________________________________________________________
© Pearson Education, Inc. All rights reserved.
b. What is the state of the water at 3 minutes?
_______________________________________________________________
c. What happens to the temperature during the time when ice is still
present in the water? Explain
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
d. What happens to the temperature after all of the ice has melted? Why?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Changes Between a Solid and a Liquid
15
sx07CAGr8_VPhyLab_07.fm Page 16 Wednesday, August 8, 2007 2:19 PM
Name ___________________________
Date ___________________
Class ____________
Lab 7: Changes Between a Liquid and a Gas
Purpose
To investigate how the temperature changes as liquid water is heated until it
becomes water vapor
Background
The particles that make up a gas have more thermal energy than particles of the
same substance in the liquid state. The particles of a liquid are in close contact
with each other while gas particles are spaced significantly further apart. The
transition from a liquid to a gas is known as vaporization and occurs by either
evaporation or boiling. The boiling point is a characteristic property of a substance
and can be used by chemists to help identify or classify the substance. The normal
boiling point is the temperature at which a substance boils at sea level. At higher
altitudes, where the air pressure is lower, the boiling point is lower.
Skills Focus
Graphing, interpreting graphs, applying concepts, relating cause and effect
1. Start Virtual Earth Science and select Changes Between a Liquid and a Gas from
the list of assignments. The lab will open in the Calorimetry laboratory. A
coffee cup calorimeter filled with 100 mL of water at 25°C is on the lab
bench. Click the clock on the wall labeled Accelerate to accelerate the
laboratory time. Click the lab book to open it. Click on the thermometer or a
part of the thermometer window to bring the thermometer window to the
front. Turn on the heater by clicking on the green light on the control panel
labeled Heat. Finally, click on the Plot window to bring it to the front.
2. Observe the temperature of the water graphed in the Plot window as a
function of time until steam begins to form above the coffee cup calorimeter.
Record, in the table, the temperature at which boiling begins. Continue to
observe the graph for three minutes. The graph will show you when three
minutes have passed. Click Save on the Plot window. A blue link will appear
in the lab book. Click on the link in the lab book to display the graph for the
time 0–3 minutes. Now click the Pressure display just below the green Exit
sign to display the pressure in the virtual laboratory. Record this pressure in
the table. The pressure is displayed on this meter only in torr. A torr is a unit
of pressure often used by chemists. 760 torr 101.3 kPa. Notice that the
pressure in the laboratory may be greater or less than 760 torr, which is
standard atmospheric pressure at sea level. Atmospheric pressure can vary
depending on the altitude of the lab and the weather.
Temperature at Boiling (°C)
16
Changes Between a Liquid and a Gas
Pressure at Boiling (torr)
© Pearson Education, Inc. All rights reserved.
Changes Between a Liquid
and a Gas
Procedure
sx07CAGr8_VPhyLab_07.fm Page 17 Thursday, July 19, 2007 8:47 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
1. Graphing In the grid below, make a sketch of how the temperature of the
water changed with time. Label the axes. Label the portion of the line where
the water is a liquid. Label the portion where the water is changing to a gas.
The blue graph line will appear on top of the black outline of the graph
boundary. You may have to look closely to see the blue graph line.
Changes Between a Liquid
and a Gas
2. a. Interpreting Graphs At what temperature does steam first begin to
form?
_______________________________________________________________
© Pearson Education, Inc. All rights reserved.
b. What is happening to the temperature of the water in the first minute as
heat is being added? Why?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
c. What is happening to the temperature as the water continues to boil and
the liquid water is changed to water vapor? Explain
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Changes Between a Liquid and a Gas
17
sx07CAGr8_VPhyLab_07.fm Page 18 Thursday, July 19, 2007 8:47 AM
Name ___________________________
Date ___________________
Class ____________
Going Further
3. Relating Cause and Effect The average or typical air pressure at sea level
is 760 torr (101.3 kPa). This pressure may vary by ±15 torr depending on the
weather. In stormy weather, the pressure at sea level drops lower than 760 torr.
In good weather, the pressure rises above 760 torr. The normal boiling point
of water is 100°C at 760 torr or 101.3 kPa. From your observation of the
boiling point and air pressure, what can you conclude?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
4. Applying Concepts From this observation, what would happen to the
boiling point of water at the top of Mt. McKinley? (The summit of Mt.
McKinley is the highest elevation in North America at 6194 m above sea
level. At this altitude there is much less atmosphere above you so the air
pressure is much lower.)
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Changes Between a Liquid
and a Gas
© Pearson Education, Inc. All rights reserved.
18
Changes Between a Liquid and a Gas
sx07CAGr8_VPhyLab_08.fm Page 19 Thursday, July 19, 2007 8:48 AM
Name ___________________________
Date ___________________
Class ____________
Lab 8: Thomson and Smaller Parts
of Atoms
Purpose
To learn how Thomson determined the charge to mass ratio of electrons
Background
As scientists began to explore the nature of atoms, their first discovery was that
an atom contains smaller, negatively charged particles. They called these
particles electrons. John Joseph (J. J.) Thomson was a physics professor at the
Cavendish Laboratory in England. Thomson found that the path of a stream of
electrons could be bent when placed between oppositely charged electric plates
(an electric field). The path of the electrons could also be bent when placed
between opposite poles of a magnet (a magnetic field). In 1897, Thomson
showed that if you could measure how much a beam of electrons was bent in
an electric field and in a magnetic field, you could determine the electron’s
charge to mass ratio. You will complete an experiment similar to Thomson’s to
understand how the scientist learned about the electron.
Skills Focus
Inferring, drawing conclusions
Procedure
1. Start Virtual Physical Science and select Thomson and Smaller Parts of Atoms
from the list of assignments. The lab will open in the Quantum laboratory.
2. What source is used in this experiment? The source is on the left. Move your
cursor over it to identify it.
__________________________________________________________________
What detector is used in this experiment? The detector is on the right. Move
your cursor over it to identify it.
__________________________________________________________________
3. Click the On/Off button to turn on the Phosphor Screen. A window will pop
up showing a close-up of the screen and the controls. The phosphor screen
detects charged particles such as electrons. It glows momentarily at the
positions where the particles hit the screen. What do you observe on the
phosphor screen?
__________________________________________________________________
Thomson and Smaller Parts of Atoms
19
Thomson and Smaller Parts
of Atoms
© Pearson Education, Inc. All rights reserved.
What type of charge do electrons have?
__________________________________________________________________
sx07CAGr8_VPhyLab_08.fm Page 20 Friday, August 10, 2007 12:39 PM
Name ___________________________
Date ___________________
Class ____________
4. To minimize overlap of windows, drag the main lab window down and left.
Drag the phosphor detector screen window up and right. Click on the Grid
button on the phosphor screen. The magnetic field controller is on the lab
bench next to the phosphor screen. Click the button above the tens place
three times to set the Magnetic Field to 30 µT. What happens to the spot from
the electron gun on the phosphor screen?
__________________________________________________________________
5. Set the Magnetic Field back to zero by clicking on the button below the tens
place three times and set the Electric Field to 10 V. What happens to the spot
from the electron gun on the phosphor screen?
__________________________________________________________________
Inferring Where should the signal on the phosphor screen be if the effects
of the electric field and magnetic field are balanced?
__________________________________________________________________
6. Drawing Conclusions Increase the magnetic field strength until the spot
reaches the center of the screen. Do this by clicking above the tens place and
then the ones place. What magnetic field balances the effect of the electric
field?
__________________________________________________________________
__________________________________________________________________
Thomson and Smaller Parts
of Atoms
20
Thomson and Smaller Parts of Atoms
© Pearson Education, Inc. All rights reserved.
Balancing the magnetic field strength with the electric field strength allowed
Thomson to make mathematical calculations to determine the charge to
mass ratio for an electron. This provided the evidence needed to convince
scientists that atoms are made of smaller parts and that one of those parts
was an electron with a negative charge.
sx07CAGr8_VPhyLab_09.fm Page 21 Wednesday, August 8, 2007 2:26 PM
Name ___________________________
Date ___________________
Class ____________
Lab 9: Rutherford and the Nucleus
Rutherford and the Nucleus
Purpose
To learn how Rutherford found evidence for the nucleus of the atom
Background
© Pearson Education, Inc. All rights reserved.
In your laboratory experiments, you have made observations and drawn
conclusions from data. But imagine that you had to do your experiments in a
dark room and couldn’t see the materials you were working with. Imagine that
the objects you were working with were so small that they couldn’t be seen
with a microscope. The early scientists who studied the atom had to work
under similar conditions. They were trying to find out about a bit of matter so
small that there was no hope of actually seeing it. Nevertheless, these atomic
scientists were able to infer that the atom has a nucleus.
A key experiment in understanding atomic structure was completed by
Ernest Rutherford in 1911. He directed a beam of positively charged particles
(alpha particles) through a gold foil and then onto a detector screen. Before
Rutherford performed his experiment, most scientists thought that electrons
were distributed in a positively charge mass like raisins in a muffin. Based on
this model, Rutherford expected that almost all the positively charged particles
would pass through the gold foil along a straight path. A few particles might be
slightly deflected because they were attracted by the negative electrons (alpha
particles have a charge of 2). Imagine his surprise when some alpha particles
veered off their straight line paths at large angles. Occasionally an alpha
particle was deflected back towards the source.
According to the raisin muffin atomic model that Rutherford was testing,
nothing in the atom was massive enough to strongly deflect an alpha particle.
Rutherford said about his results that it was “almost as incredible as if you
fired a 15-inch shell at a piece of tissue paper and it came back and hit you!” He
inferred from the experimental data that most of the mass of an atom was
concentrated in a small, positively charged nucleus at its center. This nucleus
was surrounded by mostly empty space. Electrons moved around the nucleus
in that space. Now you can make observations similar to Rutherford’s.
Skills Focus
Inferring, drawing conclusions
Procedure
1. Start Virtual Physical Science and select Rutherford and the Nucleus from the
list of assignments. The lab will open in the Quantum laboratory.
2. The experiment will be set up on the lab table. Point the cursor at the gray
box on the left side where you should see a popup describing what this
device is. What particles are emitted from this source?
_________________________________________________________________
Rutherford and the Nucleus
21
sx07CAGr8_VPhyLab_09.fm Page 22 Wednesday, August 8, 2007 2:26 PM
Rutherford and the Nucleus
Name ___________________________
Date ___________________
Class ____________
3. Point the cursor at the metal sample holder in the center. What metal foil
is used?
_________________________________________________________________
4. Point the cursor at the detector on the right. What detector is used in this
experiment?
_________________________________________________________________
5. Turn on the detector by clicking on the red/green light switch. A window
will pop up showing a close-up of the screen and the controls. The
phosphor screen detects charged particles such as alpha particles. It glows
momentarily at the positions where the particles impact the screen. The
signal in the middle of the screen represents the alpha particles coming
straight through the gold foil undeflected or only slightly deflected. What
other signals do you see on the phosphor detection screen?
_________________________________________________________________
Inferring What do these signals represent?
_________________________________________________________________
Click the Persist button (the dotted arrow) on the phosphor detector screen.
According to the raisin muffin model, what is causing the deflection of the
alpha particles?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
6. Now you will make observations at different angles of deflection. Click on
the main window to bring it to the front. Click and drag the phosphor
detection screen by its base and move it to the spotlight in the top right
corner of the table. The Persist button should still be on. Observe the
number of hits in this position as compared to the first detector position.
_________________________________________________________________
7. Move the detector to the top center spotlight position at a 90-degree angle
to the foil holder. Observe the number of hits in this spotlight position as
compared to the first detector position.
_________________________________________________________________
22
Rutherford and the Nucleus
© Pearson Education, Inc. All rights reserved.
What can you observe about the rate at which the positively charged
particles (alpha particles) hit the screen?
_________________________________________________________________
sx07CAGr8_VPhyLab_09.fm Page 23 Thursday, July 19, 2007 8:48 AM
Name ___________________________
Date ___________________
Class ____________
Rutherford and the Nucleus
8. Analyzing Cause and Effect Move the detector to the top left spotlight
position. Observe the number of hits in this spotlight position as compared
to the first detector position. What could cause the alpha particles to deflect
backwards?
_________________________________________________________________
9. How do these results disprove the raisin muffin model? Keep in mind that
there are 1,000,000 alpha particles passing through the gold foil per second.
_________________________________________________________________
_________________________________________________________________
10. Are the gold atoms composed mostly of matter or empty space?
_________________________________________________________________
11. How does the Gold Foil Experiment show that almost all of the mass of an
atom is concentrated in a small positively charged central atom?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
© Pearson Education, Inc. All rights reserved.
_________________________________________________________________
Rutherford and the Nucleus
23
sx07CAGr8_VPhyLab_10.fm Page 24 Wednesday, August 8, 2007 2:38 PM
Name ___________________________
Date ___________________
Class ____________
Lab 10: Elements and the Periodic Table
Purpose
To find out what information about the elements can be obtained from the
periodic table
Background
When you begin to study chemistry, it’s important to learn the symbols for the
common elements. In this assignment, you will go into the virtual laboratory
and create solutions in which metal elements are dissolved in water. A periodic
table can help you identify the symbols for each of these elements. You can also
obtain other information about the elements from a periodic table.
Elements and the Periodic
Table
Skills Focus
Applying concepts, drawing conclusions, classifying, making generalizations
Procedure
1. Start Virtual Physical Science and select Elements and the Periodic Table from
the list of assignments. The lab will open in the Inorganic laboratory.
3. Discard the test tube by either clicking on the red disposal bucket in the
lower right corner of the screen or by clicking and dragging the test tube
from the test tube holder and dropping it on the disposal bucket.
4. Repeat Steps 2 and 3 for each of the following elements: Sodium, Potassium,
Cobalt, Copper, Chromium, Magnesium, Barium, Calcium, Vanadium, Nickel,
and Aluminum. Record the symbol for each element and a description of the
solution of each element in each test tube in the table.
5. When you are finished, click on the Return to Lab arrow to return to the
laboratory. Then click on the door to exit the laboratory.
24
Elements and the Periodic Table
© Pearson Education, Inc. All rights reserved.
2. Observing Enter the stockroom by clicking inside the Stockroom window
at the upper right. Drag a test tube from the box and place it on the metal
test tube stand. What is the symbol used to represent silver? Identify the
bottle containing silver and click on it. This will fill the test tube with a
solution containing silver. You can see a picture of it in the picture window
in the lower left part of the screen. (Refer to a periodic table to learn the
chemical symbol for silver.) What is the color of the solution in the test tube?
Record your answers in the table below.
sx07CAGr8_VPhyLab_10.fm Page 25 Thursday, July 19, 2007 8:49 AM
Name ___________________________
Date ___________________
Class ____________
6. Complete the table for each element symbol. Use a periodic table to find
each element’s atomic number, atomic mass, and group number.
Element
Symbol
Color of
Solution
Atomic
Number
Atomic
Mass
Group
Number
Silver
Sodium
Potassium
Cobalt
Copper
Chromium
Magnesium
Elements and the Periodic
Table
Barium
Calcium
Vanadium
Nickel
Aluminum
Analyze and Conclude
1. What information about the element does the atomic number provide?
__________________________________________________________________
2. Applying Concepts How many protons and electrons does a vanadium
atom have?
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
3. Why is the atomic mass of an element an average atomic mass?
__________________________________________________________________
4. Classifying All of the elements in this experiment are metals. Place each of
the metals into one of these groups: alkali metals, alkaline-earth metals,
transition metals, or mixed group metals.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
5. Drawing Conclusions What can you conclude about the metal elements
whose solutions are colored and the metal group to which they belong?
__________________________________________________________________
__________________________________________________________________
Elements and the Periodic Table
25
sx07CAGr8_VPhyLab_11.fm Page 26 Thursday, July 19, 2007 8:49 AM
Name ___________________________
Date ___________________
Class ____________
Lab 11: Density of Solids and Liquids
Problem
To learn how density is determined for solids and for liquids
Background
Density is the mass of a substance in a given volume. The mathematical
formula for density is given below.
Mass
Density --------------------Volume
or
dm
---V
To calculate the density of a substance, you need to know both its mass and the
volume it occupies. The formula shows that to calculate density you divide the
mass by the volume. For this assignment, you will measure the masses of the
substances in grams ( g) and the volumes of both the solid and the liquid in
milliliters (mL). 1 mL is equal to 1 cm3. The unit for density in this lab will be
g/mL.
Skills Focus
Problem solving, applying concepts, developing hypotheses, making
generalizations
Procedure
Part 1 Density of a Solid
Density of Solids
and Liquids
2. Find the plastic sphere on the lab wall. Pick up the ball and drag it to the
spotlight on the balance. Record the mass in the Solid Data and Results
table.
3. On the laboratory bench, you can see a 250 mL graduated cylinder partially
filled with a unique Virtual Fluid that is used only in this virtual laboratory.
Click on the cylinder to see a zoomed-in view of the level of the fluid.
Record the volume of the Virtual Fluid in the Solid Data and Results table.
4. Drag the plastic ball to the top of the cylinder and drop it in the cylinder of
Virtual Fluid. Click the green Drop button to let the ball fall into the fluid.
Look at the close-up view window to note the new volume of the fluid.
Record the volume in the table.
5. Problem Solving How can you determine the volume of the plastic ball
from your measurements?
_________________________________________________________________
_________________________________________________________________
26
Density of Solids and Liquids
© Pearson Education, Inc. All rights reserved.
1. Start Virtual Physical Science and select Density of Solids and Liquids from
the list of assignments. The lab will open in the Density laboratory.
sx07CAGr8_VPhyLab_11.fm Page 27 Thursday, July 19, 2007 8:49 AM
Name ___________________________
Date ___________________
Class ____________
Record the volume of the plastic sample in the Solid Data and Results table.
Click the blue handle at the bottom of the cylinder to empty the contents of
the cylinder.
Solid Data and Results
Sample
Mass of
Sample
(g)
Volume of
Virtual Fluid
(mL)
Volume of
Virtual
Fluid and
Sample
(mL)
Volume
of
Sample
(mL)
Density
(g/mL)
Plastic
Part 2 Density of a Liquid
6. Toggle through the fluids on the Fluid Control switch with the gray arrows
until you find Alcohol. Click the Full button underneath the display to
select the amount of fluid to be added to the cylinder. Click the Fill button
to fill the graduated cylinder with the alcohol. Click on the cylinder to see a
zoomed-in view of the level of the fluid. Record the volume of the alcohol
in the Liquid Data and Results table.
7. Click the Tare button on the balance. Taring the balance rezeros the balance
with whatever is on it. Drag the beaker on the counter to the balance and
record its mass in the Liquid Data and Results table. Drag the beaker back
to the spotlight on the counter.
8. Pick up the cylinder filled with alcohol and pour it into the empty beaker.
Drag the beaker to the balance and record the mass of the alcohol and
beaker in the Liquid Data and Results table.
Density of Solids
and Liquids
© Pearson Education, Inc. All rights reserved.
9. Problem Solving How can you determine the mass of the alcohol in the
beaker?
_________________________________________________________________
_________________________________________________________________
Record the mass of the alcohol in the Liquid Data and Results table.
10. Calculating Using the formula for density, calculate the density of the
plastic ball and record the answer in the Solid Data and Results table.
Similarly, calculate the density of the alcohol and record the answer in the
Liquid Data and Results table.
Density of Solids and Liquids
27
sx07CAGr8_VPhyLab_11.fm Page 28 Thursday, July 19, 2007 8:49 AM
Name ___________________________
Date ___________________
Class ____________
Liquid Data and Results
Sample
Mass of
Empty
Beaker
(g)
Mass of
Beaker
and
Sample
(g)
Mass of
Sample
(g)
Volume
of
Sample
(mL)
Density
(g/mL)
Alcohol
Analyze and Conclude
1. Applying Concepts When you determined the volume of the plastic ball,
it was completely submerged. What if the ball floated at the top of the fluid
and was not completely covered by the Virtual Fluid? How would this affect
the measured volume of the solid? Explain.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
2. Applying Concepts Why do some materials float in water and others sink?
__________________________________________________________________
__________________________________________________________________
Density of Solids
and Liquids
__________________________________________________________________
__________________________________________________________________
Test your hypothesis by pouring a sample of alcohol into the graduated
cylinder and dropping the plastic ball into it.
4. Making Generalizations If you had several samples, both solids and
liquids, what measurements and calculations would you need to make to
determine whether a sample would float or sink when placed with the
others?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
28
Density of Solids and Liquids
© Pearson Education, Inc. All rights reserved.
3. Developing Hypotheses If the plastic ball were placed in the alcohol,
would it float or sink?
__________________________________________________________________
sx07CAGr8_VPhyLab_12.fm Page 29 Thursday, July 19, 2007 9:00 AM
Name ___________________________
Date ___________________
Class ____________
Lab 12: Creating Chemical Compounds
Purpose
To determine the ratio of elements in a chemical compound
Background
Matter can consist of a single element, but more often matter is made up of
chemical compounds. A chemical compound consists of two or more elements
combined in a set ratio. A ratio compares two numbers. It tells you the amount
of one item compared to the amount of another item. The formula for a
chemical compound shows the ratio of the elements in the compound. For
example, you are familiar with table salt, a chemical compound made from
sodium (Na) and chlorine (Cl). The chemical formula for table salt is NaCl. The
formula shows that the ratio of sodium atoms to chlorine atoms is 1:1.
You are also familiar with a compound called rust, which is made from iron
(Fe) and oxygen (O). The chemical formula for rust is Fe2O3. The small number
to the right of each symbol is a subscript. The subscripts tell you that a
molecule of rust contains two iron atoms (Fe) combined with three oxygen
atoms (O). The ratio of iron atoms to oxygen atoms in rust is 2:3.
When elements combine to form compounds, the compounds have
different properties from those of the combining elements. Color is a property
that can change in a chemical reaction, so a color change is evidence that a
chemical reaction may have occurred.
Skills Focus
Observing, applying concepts, predicting
Procedure
2. Enter the stockroom by clicking inside the Stockroom window. Once inside
the stockroom, drag a test tube from the box and place it on the metal test
tube stand. Click on the bottle of Ag solution on the shelf to add it to the
test tube. Click Done to send the test tube back to the lab. If you make a
mistake in selecting the correct solution, drag the test tube to the red
disposal bucket and begin again.
3. Drag another test tube from the box and place it on the metal test tube stand.
Click on the bottle of Pb2 solution on the shelf to add it to the test tube.
Click Done to send the test tube back to the lab. Repeat this process and
create test tubes containing Fe3 (not Fe2), Cu2, Pb2 (again), and Ag
(again). Click Done after each test tube. Click on the Return to Lab arrow
when finished with all test tubes. You should now be in the laboratory. Six
test tubes should be in the test tube rack.
Creating Chemical Compounds
Creating Chemical
Compounds
© Pearson Education, Inc. All rights reserved.
1. Start Virtual Physical Science and select Creating Chemical Compounds from
the list of assignments. The lab will open in the Inorganic laboratory.
29
sx07CAGr8_VPhyLab_12.fm Page 30 Wednesday, August 8, 2007 2:42 PM
Name ___________________________
Date ___________________
Class ____________
4. Click on the handle just above the periodic table to pull down the TV screen.
The screen will display the chemical formula of the compound in the test
tube as you move the cursor over a test tube. Observe the changes that occur
in the test tube in the display in the lower left corner. Notice the changes in
chemical formulas on the TV screen above. Move the hand over the first test
tube on the left. Observe that the solution is clear and colorless in the lower
left window and that the screen shows Ag.
5. Drag the first test tube (Ag) from the blue test tube rack to the metal test
tube stand on the lab bench. Click the bottle labeled NaCl on the top shelf.
Notice the changes in the test tube and in the screen. The solution changes
from colorless to white and the screen shows AgCl. In this compound the
ratio of Ag to Cl is 1:1. Record the formula, the color before reaction, the
color after reaction, and the ratio in the table on the next page. Drag the test
tube to the red disposal bucket on the lower right. Do NOT click on Clear All.
6. Drag the second test tube (Pb2) from the blue rack to the metal stand and
click the bottle labeled NaCl on the top shelf. What changes do you observe
in the test tube and in the screen? Record the color before, the color after, and
the ratio in the table. Drag the test tube to the red disposal bucket.
7. Drag the third test tube (Fe3) from the blue rack to the metal stand but this
time click the bottle labeled Na2S on the top shelf. Record the color before,
the color after, and the ratio in the table. Drag the test tube to the red
disposal bucket. Repeat for the fourth (Cu2) and fifth (Pb2) test tubes
adding Na2S in each case. Record the color before, the color after, and the
ratio in the table. Drag the test tubes to the red disposal bucket.
Click the bottle labeled Na2S. Record the color before, the color after, and the
ratio in the table. Drag the test tube to the red disposal bucket.
Creating Chemical
Compounds
If you leave the spoon made of silver in mayonnaise, the silver metal turns
dark. This is because mayonnaise is made from eggs which contain sulfur.
The silver of the spoon and the sulfur from the eggs in the mayonnaise form
the same compound you just created. The compound is called silver sulfide
(Ag2S). The silver sulfide that forms on silver spoons and other silver objects
is called tarnish. To remove tarnish, you must use a special cleaner and
polish the object with a soft cloth.
30
Creating Chemical Compounds
© Pearson Education, Inc. All rights reserved.
8. Predicting Drag the last test tube (Ag) to the rack. From your
observations of the last three solutions, what color do you predict when
Na2S is added to the Ag solution?
__________________________________________________________________
sx07CAGr8_VPhyLab_12.fm Page 31 Thursday, July 19, 2007 9:00 AM
Name ___________________________
Test
Tube
Formula
From
Screen
Date ___________________
Color
Before
Color
After
Class ____________
Ratio
Analyze and Conclude
1. Infer from your data what must be the charge of the oxygen ion, if lead
forms the compound PbO?
__________________________________________________________________
2. Could the compound CuFe form? Explain your answer.
__________________________________________________________________
Creating Chemical
Compounds
© Pearson Education, Inc. All rights reserved.
3. Tin (Sn) forms the ion Sn4+. What must be the formula for tin chloride?
__________________________________________________________________
Creating Chemical Compounds
31
sx07CAGr8_VPhyLab_13.fm Page 32 Thursday, July 19, 2007 9:00 AM
Name ___________________________
Date ___________________
Class ____________
Names and Formulas
of Ionic Compounds
Lab 13: Names and Formulas
of Ionic Compounds
Purpose
To investigate how ions combine to form ionic compounds and learn how to
name and write the formulas for these compounds
Background
Skills Focus
Applying concepts
Procedure
1. Start Virtual Physical Science and select Names and Formulas of Ionic
Compounds from the list of assignments. The lab will open in the Inorganic
laboratory.
2. Enter the stockroom by clicking inside the Stockroom window at the upper
right of the lab. Once inside the stockroom, drag a test tube from the box and
place it on the metal test tube stand. Click on the bottle of Ag ion solution
on the shelf to add it to the test tube. Click Done to send the test tube back to
the lab. Click on the Return to Lab arrow.
32
Names and Formulas of Ionic Compounds
© Pearson Education, Inc. All rights reserved.
An ion is an atom or group of atoms that has a positive or negative charge.
Positive ions are formed when an atom loses one or more electrons. Negative
ions are formed when an atom gains one or more electrons. Ions that contain
only one atom are known as monatomic ions. Ions that contain more than one
atom are called polyatomic ions.
When positive and negative ions combine to form an ionic compound, the
ratio of the positive ion to negative ion is such that the charges on the ions are
balanced. That means that all the charges add up to zero and the compound
has no charge. For example, the charge on a sodium ion is 1 (Na+). The charge
on a chloride ion is 1– (Cl–). The compound formed between these two ions is
sodium chloride with the formula NaCl. The subscripts in a formula tell you
how many atoms of an element are needed to balance the positive and negative
charges. In NaCl the subscripts are understood to be one. The 1+ charge on one
sodium ion balances the 1– charge on one chloride ion.
When the magnesium ion (Mg2+) and the bromide ion (Br–) combine, the
formula for the compound formed is MgBr2. The subscript 2 is required on the
bromide ion. Two negatively charged bromide ions (2 1) are needed to
balance the 2 charge of one magnesium ion. The name of the compound is
magnesium bromide.
sx07CAGr8_VPhyLab_13.fm Page 33 Wednesday, August 8, 2007 2:46 PM
Name ___________________________
Date ___________________
Class ____________
Names and Formulas
of Ionic Compounds
3. Place the test tube containing the Ag solution in the metal test tube stand.
Click on the Divide button on the bottom (with the large red arrow) four
times to make four additional test tubes containing Ag. With one test tube
in the metal stand and four duplicates in the blue rack, click on the Na2S
bottle located on the lab bench to add Na2S solution. The solution contains
both Na and S2 ions, but the S2 ion is what will combine, as indicated
in the table below.
Observe what happens in the window at the bottom left. Record your
observation in the Observation Table below. If the solution remains the
same, record NR, for no reaction. Drag this test tube to the red disposal
bucket on the right.
4. Place a second Ag tube from the blue rack on the metal stand. This time
add NaCl. Record your observations and discard the tube. Use the next Ag
tube, but add Na2SO4. Record your observations. Use the next Ag tube, but
add NaOH, and record your observations. With the last Ag tube add
Na2CO3 and record your observations. When you are finished, click on the
red disposal bucket to clear the lab.
5. Return to the stockroom and repeat Steps 3 and 4 using Pb2, Fe3, and Cu2.
© Pearson Education, Inc. All rights reserved.
Analyze and Conclude
In the tables below, you will be using the data you have collected to determine
the compound formulas and names.
The cells of the first column of the three tables contain: (1) the label from the
bottle used, (2) the negative monatomic or polyatomic ion (with the charge) to
be used in the chemical formula, and (3) the name of the ion or polyatomic ion
to be used in the name. The cells in the top row of each table contain: (1) the
positive ion (with the charge) to be used in the chemical formula, and (2) the
name of the element to be used in the chemical name.
Using this information, write in the Chemical Formula Table the correct
chemical formula for each combination that produced a reaction. Write in the
Chemical Name Table the correct chemical name for each combination that
produced a reaction. In all three tables write NR for each combination that did
not produce a chemical reaction.
Make certain that you balance the positive and negative charges by using
subscripts in the chemical formula. If more than one polyatomic ion is required
in a formula, place parentheses around it. For example, the positive aluminum
ion (Al3) and the negative polyatomic ion sulfate (SO42) form the compound
aluminum sulfate. The chemical formula for aluminum sulfate is Al 2(SO4)3
because 2 (3) for the aluminum ion is 6 and 3 (2) for the sulfate ion is
6. The 6 and 6 add to zero charge for the compound.
Names and Formulas of Ionic Compounds
33
sx07CAGr8_VPhyLab_13.fm Page 34 Thursday, July 19, 2007 9:00 AM
Name ___________________________
Date ___________________
Class ____________
Observation Table
Names and Formulas
of Ionic Compounds
Ag
silver
Pb2
lead
Fe3
iron
Cu2
copper
Na2S (S2) sulfide
NaCl (Cl) chloride
Na2SO4 (SO42) sulfate
NaOH (OH) hydroxide
Na2CO3 (CO32)
carbonate
Chemical Formula Table
Ag
silver
Pb2
lead
Fe3
iron
Cu2
copper
Na2S (S2) sulfide
NaCl (Cl) chloride
Na2SO4 (SO42) sulfate
Na2CO3 (CO32)
carbonate
34
Names and Formulas of Ionic Compounds
© Pearson Education, Inc. All rights reserved.
NaOH (OH)
hydroxide
sx07CAGr8_VPhyLab_13.fm Page 35 Wednesday, August 8, 2007 2:46 PM
Name ___________________________
Date ___________________
Class ____________
Chemical Name Table
Pb2
lead
Fe3
iron
Cu2
copper
Names and Formulas
of Ionic Compounds
Ag
silver
Na2S (S2) sulfide
NaCl (Cl) chloride
Na2SO4 (SO42) sulfate
NaOH (OH)
hydroxide
Na2CO3 (CO32)
carbonate
1. The sulfate ion has the formula SO42. What are the formulas for the
compounds made when the sulfate ion combines with Ag, Pb2 and Fe3?
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
2. What are the names for the following compounds: CaS, Mg(OH) 2, KOH?
__________________________________________________________________
Names and Formulas of Ionic Compounds
35
sx07CAGr8_VPhyLab_14.fm Page 36 Thursday, July 19, 2007 9:01 AM
Name ___________________________
Date ___________________
Class ____________
Lab 14: Describing Chemical Reactions
Purpose
To represent double replacement reactions by balanced chemical equations
Describing Chemical
Reactions
Background
A chemical equation is a shorthand way to show what happens in a chemical
reaction. In chemical equations, chemical symbols and formulas are used
instead of words. The formulas of the reactants (the substances you start with)
are placed on the left side of a right-pointing arrow. The products (the new
substances formed by the reaction) are placed on the right side of the arrow. In
this experiment, you will observe double replacement reactions. In a double
replacement reaction, ions in one compound appear to “trade places” with ions
in another compound. The general form of a double replacement equation is
AB CD → CB AD. A and C represent positive ions. B and D represent
negative ions. Note that in the equation, ions A and C trade places.
Skills Focus
Applying concepts, predicting
Procedure
1. Start Virtual Physical Science and select Describing Chemical Reactions from
the list of assignments. The lab will open in the Inorganic laboratory.
3. Drag the test tube containing the Ag+ from the blue rack to the metal test
tube stand. Click on the NaOH bottle on the reagent shelf. Observe what
happens in the window at the bottom left. Record your observation. Drag
this test tube to the red disposal bucket on the right.
__________________________________________________________________
__________________________________________________________________
36
Describing Chemical Reactions
© Pearson Education, Inc. All rights reserved.
2. Click in the Stockroom. Drag a test tube from the box and place it on the
metal test tube stand. Click on the bottle of Ag+ metal ion solution on the
shelf to add it to the test tube. Click Done to send the test tube back to the
lab. Click on the Return to Lab arrow.
sx07CAGr8_VPhyLab_14.fm Page 37 Thursday, July 19, 2007 9:01 AM
Name ___________________________
Date ___________________
Class ____________
4. The silver ion solution obtained from the stockroom is silver nitrate
(AgNO3). When it is mixed with sodium hydroxide (NaOH), the chemical
reaction that occurs can be described in words as follows:
Silver nitrate reacts with sodium hydroxide to form
sodium nitrate and silver hydroxide.
The description can also be written in chemical formulas as follows:
AgNO3 + NaOH → NaNO3 + AgOH(s)
The (s) after AgOH indicates that the solution turned cloudy because a solid
precipitate of AgOH formed. The equation is balanced. The same number and
kind of elements are on the left and on the right of the arrow. Note that as a
result of the reaction, the Ag+ ion and the Na+ ion “traded places.” This is a
double replacement reaction.
Describing Chemical
Reactions
5. Return to the Stockroom. Drag a test tube from the box and place it on the
metal test tube stand. Click on the bottle of Pb2+ metal ion solution on the
shelf to add it to the test tube. Click Done to send the test tube back to the
lab. Click on the Return to Lab arrow.
6. Drag the test tube containing Pb2+ from the blue rack to the metal test tube
stand. Click on the Na2CO3 bottle on the reagent shelf. Observe what
happens in the window at the bottom left. Record your observation. Drag
this test tube to the red disposal bucket on the right.
__________________________________________________________________
Analyze and Conclude
1. Applying Concepts The Pb2+ solution is lead nitrate, Pb(NO3)2. When
Pb(NO3)2 is mixed Na2CO3 the chemical reaction is described in words as
follows:
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Lead nitrate reacts with sodium carbonate to form
sodium nitrate and lead carbonate.
Write a balanced chemical equation using chemical formulas to represent this
chemical reaction. Note the charges on the ions: Pb2+, NO3, Na+, and CO32.
You must balance the charges of the ions when writing the formulas for the
compounds. When you have written the complete equation, balance the
elements on both sides of the arrow.
Describing Chemical Reactions
37
sx07CAGr8_VPhyLab_14.fm Page 38 Thursday, July 19, 2007 9:01 AM
Name ___________________________
Date ___________________
Class ____________
2. Predicting Suppose that silver nitrate solution (AgNO3) and sodium
sulfide solution (Na2S) were mixed. Write a word description of the double
replacement reaction that would occur.
__________________________________________________________________
3. Write a balanced chemical equation using chemical formulas to represent
the reaction described in 2. The sulfide ion is S2–.
__________________________________________________________________
4. You can observe the chemical reaction in 3 by obtaining Ag+ from the
Stockroom and mixing it with Na2S. Record your observations.
__________________________________________________________________
Describing Chemical
Reactions
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
38
Describing Chemical Reactions
sx07CAGr8_VPhyLab_15.fm Page 39 Thursday, July 19, 2007 9:02 AM
Name ___________________________
Date ___________________
Class ____________
Lab 15: Using Energy to Observe
Chemical Changes
Purpose
To measure temperature changes in a chemical reaction and infer whether the
reaction is endothermic or exothermic
Background
Energy changes occur during chemical reactions. Some reactions absorb
energy. Energy must be added to these reactions to cause them to occur.
Reactions that absorb energy are known as endothermic reactions. Cooking
food is an example of an endothermic reaction. Other reactions release energy.
Reactions that release energy are known as exothermic reactions. Burning fuel
to drive a car is an example of an exothermic reaction.
Skills Focus
Calculating, classifying, applying concepts
Procedure
1. Start Virtual Physical Science. Select Using Energy to Observe Chemical
Changes from the list of assignments. The lab will open in the Calorimetry
laboratory.
2. A bottle of sodium chloride (NaCl) is on the lab bench. A weighing paper is
on the balance with approximately 2 g of sodium chloride (NaCl) on the
paper.
© Pearson Education, Inc. All rights reserved.
Using Energy to Observe
Chemical Changes
3. The calorimeter on the lab bench contains 100 cm3 of water. Click the Lab
Book to open it. Make certain the stirrer is On. You should be able to see the
stirrer shaft rotating. In the thermometer window, click Save to begin
recording data. Allow 20–30 seconds to obtain a baseline temperature of the
water.
4. Drag the weighing paper with the sample to the calorimeter until it snaps
in place. Pour the sample into the calorimeter. You can click on the Accelerate
button (the clock) to accelerate the time in the laboratory. Observe the
change in temperature until it levels off and then record data for an
additional 20–30 seconds. Click Stop. A blue data link will appear in the Lab
book. Click the blue data link and record the initial and final water
temperatures in the table below. Click the red disposal bucket to clear
the lab.
5. Click on the Stockroom to enter. Click on the clipboard and select Preset
Experiment #7: Heat of Solution NaNO3. Click Return to Lab. Repeat the
experiment with sodium nitrate (NaNO3). Record the initial and final
temperatures in the table. Click the red disposal bucket to clear the lab.
Using Energy to Observe Chemical Changes
39
sx07CAGr8_VPhyLab_15.fm Page 40 Thursday, July 19, 2007 9:02 AM
Name ___________________________
Date ___________________
Class ____________
6. Click on the Stockroom to enter. Click the clipboard and select Preset
Experiment #8: Heat of Solution NaAc. Click Return to Lab. Repeat the
experiment with sodium acetate, NaCH3COO (NaAc). Record the initial and
final temperatures in the table. Click the red disposal bucket to clear the lab.
Mixture
Initial Temperature
T1 (ºC)
Final Temperature
T2 (ºC)
NaCl(s) + H2O (l)
NaNO3(s) + H2O (l)
NaCH3COO(s) + H2O (l)
Analyze and Conclude
1. Calculating Find the change in temperature for each mixture.
Change in Temperature = T2 T1
__________________________________________________________________
3. Classifying Which solution(s) had little or no change in temperature
( 0.30°C)?
__________________________________________________________________
4. Applying Concepts When sodium chloride dissolves in water, the ions
dissociate or break apart in solution.
NaCl(s) → Na+(aq) + Cl–(aq)
Write ionic equations, similar to the one above, that describe how NaNO 3 and
NaCH3COO dissociate as they dissolve in water. Include heat as a reactant on
the left side of the equation or as a product on the right side of the equation.
40
Using Energy to Observe Chemical Changes
© Pearson Education, Inc. All rights reserved.
Using Energy to Observe
Chemical Changes
2. Classifying An exothermic process gives off heat. The reaction mixture
warms up and the sign of the change in temperature is positive. An
endothermic process absorbs heat. The reaction mixture cools off and the
sign of the change in temperature is negative. Which solution(s) are
endothermic and which are exothermic?
__________________________________________________________________
sx07CAGr8_VPhyLab_16.fm Page 41 Wednesday, August 8, 2007 2:49 PM
Name ___________________________
Date ___________________
Class ____________
Lab 16: Boiling Point Elevation
Purpose
To find out how the boiling point of water changes when a substance is
dissolved in it
Background
Pure water boils at 100°C when the pressure of the atmosphere is 101.3 kPa
or 760 torr. But if you dissolve a substance such as table salt (NaCl) in water,
the boiling point of the solution is higher than 100°C. This difference is called
boiling point elevation. In this assignment, you will dissolve a sample of NaCl
in water and measure the boiling point elevation for the solution.
Skills Focus
Calculating, relating cause and effect, predicting, controlling variables,
drawing conclusions
Procedure
1. Start Virtual Physical Science. Select Boiling Point Elevation from the list of
assignments. The lab will open in the Calorimetry laboratory. A calorimeter
is on the lab bench. A sample of sodium chloride (NaCl) is on the balance.
Record the mass in Table 1.
3. Continue to observe the temperature until the first appearance of steam
comes from the calorimeter. Immediately click the red light on the heater to
turn it off and quickly note the temperature. Record the temperature as the
boiling point of pure water in Table 1. Letting the water continue to boil will
decrease the mass of the water present in the calorimeter. Note that the
boiling point may not be exactly 100°C if the atmospheric pressure is not
760 torr. (Torr is a unit of pressure often used by chemists. Normal
atmospheric pressure at sea level is 760 torr. 760 torr = 101.3 kPa.) The
current atmospheric pressure can be checked by selecting Pressure on the
LED meter on the wall.
Boiling Point Elevation
Boiling Point Elevation
© Pearson Education, Inc. All rights reserved.
2. The calorimeter already contains 100 cm3 of water. Make certain the stirrer is
On. You should be able to see the shaft rotating. Click on the green heater
light on the control panel to turn on the heater and begin heating the water.
Click the clock on the wall labeled Accelerate to accelerate the laboratory
time. The temperature is displayed in the thermometer window on the left.
Observe the temperature closely. Click the clock to turn off time acceleration
at approximately 90°C.
41
sx07CAGr8_VPhyLab_16.fm Page 42 Thursday, July 19, 2007 9:02 AM
Name ___________________________
Date ___________________
Class ____________
4. Drag the weighing paper from the balance to the calorimeter and add the
NaCl. Wait 30 seconds for the salt to dissolve and then turn on the heater.
When steam first appears, observe and record the temperature in Table 1.
Table 1
Mass of NaCl (g)
Boiling temperature of pure water (ºC)
Boiling temperature of solution (ºC)
Change in boiling temperature (ºC)
Analyze and Conclude
1. What happened to the boiling temperature when the NaCl was added to the
water?
__________________________________________________________________
2. Calculating What is the difference between the boiling temperature of
pure water and the boiling temperature of water with dissolved NaCl?
Record the difference in Table 1.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
4. Predicting What effect do you think an increase in the mass of dissolved
NaCl would have on the boiling temperature?
__________________________________________________________________
5. Controlling Variables You will conduct an experiment to determine the
answer. What variables should remain constant?
__________________________________________________________________
Boiling Point Elevation
What is the manipulated variable?
__________________________________________________________________
What will be the responding variable?
__________________________________________________________________
6. Click on the red disposal bucket to clear the lab. Click on the Stockroom.
Click on the clipboard and select Preset Experiment #2: Boiling Point
Elevation – NaCl.
42
Boiling Point Elevation
© Pearson Education, Inc. All rights reserved.
3. Relating Cause and Effect On a hot summer day the car that you are
riding in stalls. It has overheated because of lack of proper coolant. Explain
how radiator coolant works.
__________________________________________________________________
sx07CAGr8_VPhyLab_16.fm Page 43 Wednesday, August 8, 2007 2:49 PM
Name ___________________________
Date ___________________
Class ____________
7. A calorimeter and bottle of NaCl are on the table. Click Return to Lab. There
will already be a quantity of NaCl on the scale. Record the mass in Table 2.
8. Repeat Steps 2–4 of the procedure above using your new sample mass.
Record your data in Table 2. Because you have increased your mass, you
will need to wait a little longer for the NaCl to dissolve. The heater will not
turn on until all of the salt dissolves.
Table 2
Mass of NaCl (g)
Boiling temperature of pure water (ºC)
Boiling temperature of solution (ºC)
Change in boiling temperature (ºC)
9. Drawing Conclusions Compare the boiling point elevation in Table 1 with
the boiling point elevation in Table 2. What effect did the increased mass of
NaCl have on the boiling point elevation of the solutions? Explain.
__________________________________________________________________
__________________________________________________________________
Boiling Point Elevation
© Pearson Education, Inc. All rights reserved.
__________________________________________________________________
Boiling Point Elevation
43
sx07CAGr8_VPhyLab_17.fm Page 44 Thursday, August 9, 2007 6:56 AM
Name ___________________________
Date ___________________
Class ____________
Lab 17: Endothermic vs. Exothermic
Endothermic vs.
Exothermic
Problem
To examine how adding different solutes can raise or lower the temperature of
a solution
Background
In virtually all chemical reactions, heat is either absorbed or released. A
chemical change that absorbs heat (heat in) is termed endothermic. A chemical
change that releases heat is called exothermic (heat out). By measuring
temperature changes associated with chemical reactions, a process can be
identified as an endothermic or exothermic change. In this assignment, you
will dissolve several salts in water, measure the resulting temperature change,
and then make deductions about the nature of the process.
Skills Focus
Measuring, classifying, applying concepts
Procedure
1. Start Virtual Physical Science and select Endothermic vs. Exothermic from the
list of assignments. The lab will open in the Calorimetry laboratory.
2. A bottle of sodium chloride (NaCl) is visible on the lab bench. A weigh
paper is on the balance with approximately 2g of NaCl on the paper. A
calorimeter containing 100 mL water is on the lab bench.
4. Drag the weigh paper with the sample to the calorimeter until it snaps into
place above the calorimeter and then release to pour the sample into the
calorimeter. Observe the change in temperature until it reaches a maximum
and then record data for an additional 20–30 seconds. Click Stop. (You can
click on the clock on the wall labeled Accelerate to accelerate the time in the
laboratory.) A blue data link will appear in the lab book. Click the data link
and record the temperature before adding the NaCl and the highest or
lowest temperature after adding the NaCl in the data table.
5. Click the red disposal bucket to clear the lab. Click on the Stockroom to
enter. Click on the clipboard and select Preset Experiment #7: Heat of
Soution—NaNO3 and repeat the experiment with NaNO3. Record the initial
and final temperatures in the data table.
44
Endothermic vs. Exothermic
© Pearson Education, Inc. All rights reserved.
3. Click the Lab Book to open it. Make certain the stirrer is On (you should be
able to see the shaft rotating). In the thermometer window, click Save to
begin recording data. Allow 20–30 seconds to obtain a baseline temperature
of the water.
sx07CAGr8_VPhyLab_17.fm Page 45 Thursday, August 9, 2007 6:57 AM
Name ___________________________
Date ___________________
Class ____________
6. Click the red disposal bucket to clear the lab. Click on the Stockroom to enter.
Click the clipboard and select Preset Experiment #8: Heat of Solution—NaAc
and repeat the experiment with NaCH3COO (NaAc). Record the initial and
final temperatures in the data table.
Endothermic vs.
Exothermic
7. Click the red disposal bucket to clear the lab. Click on the Stockroom to
enter. Click the clipboard and select Preset Experiment #6: Heat of Solution—
NaOH and repeat the experiment with NaOH. Record the initial and final
temperatures in the data table.
Data Table
T1
T2
T(T2 T1)
Exothermic or
Endothermic?
NaCl (s) + H2O (l)
NaNO3 (s) + H2O (l)
NaCH3COO (s)+ H2O (l)
NaOH (s) + H2O (l)
Use your experimental data to answer the following questions.
8. Calculate T (T T2 T1) for each mixture and record it in the data
table.
© Pearson Education, Inc. All rights reserved.
9. Classifying An exothermic process gives off heat (warms up). An
endothermic process absorbs heat (cools off). Which solutions are
endothermic and which are exothermic? Record in the data table.
10. Applying Concepts NaCl, commonly known as salt, is often sprinkled on
icy roads and sidewalks to melt the ice. From what you have observed in
this lab, explain why this is done? (Hint: This process is called freezing
point lowering.)
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Endothermic vs. Exothermic
45
sx07CAGr8_VPhyLab_17.fm Page 46 Thursday, August 9, 2007 6:57 AM
Endothermic vs.
Exothermic
Name ___________________________
Date ___________________
Class ____________
11. Applying Concepts NaOH is commonly used in drain cleaning products
to clean out drains because the heat generated can help dissolve the clogs.
What other common endothermic or exothermic chemical products can
you think of?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
46
Endothermic vs. Exothermic
sx07CAGr8_VPhyLab_18.fm Page 47 Thursday, August 9, 2007 6:58 AM
Name ___________________________
Date ___________________
Class ____________
Lab 18: Acid–Base Reactions
Purpose
To study a neutralization reaction and the role that pH and indicator color play
in a titration
Background
A reaction between an acid and a base is called a neutralization reaction. The
acid solution before the reaction has a low pH. The base solution before the
reaction has a high pH. When acid and base solutions of equal concentration
are mixed in equal amounts, they neutralize each other. The resulting solution
has a pH of 7 or close to 7. A neutralization reaction is a double replacement
reaction. The products formed are water and a salt. A titration is a process used
by chemists to determine the concentration of acid or base in a sample.
Acid–Base Reactions
Skills Focus
Observing, relating cause and effect, applying concepts, interpreting graphs
Procedure
© Pearson Education, Inc. All rights reserved.
1. Start Virtual Physical Science. Select Acid–Base Reactions from the list of
assignments. The lab will open in the Titrations laboratory.
2. Click the Lab Book to open it. The buret (long, glass measuring tube) is filled
with NaOH. The beaker contains 25.00 cm3 of HCl with a small amount of
bromocresol green as an indicator. The horizontal position of the orange
handle is the off position for the buret valve. Open the buret valve by
pulling down on the orange handle. The vertical position delivers solution
the fastest. There are three intermediate rates in between. Turn the orange
handle to one of the faster positions. Observe the titration curve in the Plot
window. Also observe the color of the solution in the beaker and carefully
note in the Buret Zoom View the volume of NaOH at which the solution
changes color. When the volume reaches 35 cm3, double-click the orange
handle to stop the titration. Click Save in the Plot window. A blue data link
will be created in the lab book. Click on it to view the titration graph.
If you need to repeat the titration, click in the Stockroom to enter. Click on the
clipboard, and select Preset Experiment #1: Strong Acid–Strong Base. If you do
this, the graph will contain a blue line and an additional red line. Disregard the
red line.
Acid–Base Reactions
47
sx07CAGr8_VPhyLab_18.fm Page 48 Thursday, July 19, 2007 9:10 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
1. Observing What was the color of the solution in the beaker at the
beginning of the titration?
__________________________________________________________________
What was the color of the solution in the beaker at the end of the titration?
__________________________________________________________________
2. Observing At about what volume of NaOH did the color change from
yellow to blue? (You may need to repeat the experiment and observe the
Buret Zoom View.)
__________________________________________________________________
Acid–Base Reactions
3. Relating Cause and Effect What occurred in the graph of pH vs. volume
at this volume?
__________________________________________________________________
What occurred during the titration that would cause the color of the
indicator to change?
__________________________________________________________________
__________________________________________________________________
4. Applying Concepts The chemical reaction between hydrochloric acid
(HCl) and sodium hydroxide base (NaOH) is both a neutralization and a
double replacement reaction. Write a balanced chemical equation to
represent the chemical reaction you observed.
__________________________________________________________________
What makes NaOH a base?
__________________________________________________________________
When the neutralization reaction is complete, what has become of the
hydrogen and hydroxide ions?
__________________________________________________________________
Because water is neutral, what causes the neutralization of an acid and a
base?
__________________________________________________________________
6. What is the salt formed in this neutralization reaction?
__________________________________________________________________
48
Acid–Base Reactions
© Pearson Education, Inc. All rights reserved.
5. Relating Cause and Effect What makes HCl an acid?
__________________________________________________________________
sx07CAGr8_VPhyLab_18.fm Page 49 Thursday, July 19, 2007 9:10 AM
Name ___________________________
Date ___________________
Class ____________
7. Examine the graph of pH vs. volume (blue line) and sketch the titration
curve below.
Acid–Base Reactions
© Pearson Education, Inc. All rights reserved.
8. Interpreting Graphs What is the pH when the volume of added NaOH is
25.00 cm3?
__________________________________________________________________
Acid–Base Reactions
49
sx07CAGr8_VPhyLab_19.fm Page 50 Thursday, August 9, 2007 6:59 AM
Name ___________________________
Date ___________________
Class ____________
Lab 19: Energy of a Chemical Reaction
Purpose
To discover how energy changes during a chemical reaction
Background
Energy changes occur in all chemical reactions. Some reactions absorb energy,
which means that energy must be added to cause the reaction to occur.
Chemical reactions that absorb energy are known as endothermic reactions.
Cooking food is an endothermic reaction. Other reactions release energy. These
are called exothermic reactions. A campfire is an example of an exothermic
reaction.
Chemists measure the energy released in a chemical reaction using a bomb
calorimeter. In a bomb calorimeter a sample is burned in a constant-volume
chamber in the presence of oxygen at high pressure. The constant-volume
chamber, or bomb, is surrounded by a measured amount of water. The heat
released by the reaction in the bomb warms the water that surrounds it. In this
experiment, you will combust (or burn in oxygen) a sample of chicken fat.
Skills Focus
Interpreting graphs, calculating, interpreting data, drawing conclusions
Procedure
Energy of a Chemical
Reaction
2. Click on the Lab Book to open it.
3. Some of the parts of the calorimeter will be identified when the cursor
moves over them. To assemble the calorimeter, double-click the following
items in numerical order: (1) the cup of chicken fat on the balance pan, (2)
the bomb head, (3) the screw cap, and (4) the bomb. Click the calorimeter lid
to close it. Combustion experiments can take a long time. Click the clock on
the wall labeled Accelerate to accelerate the laboratory time.
4. Click the Bomb Control Panel and the Plot window to bring them to the front.
If the Plot window has been closed, click the Graph button on the Bomb
Control Panel. Click the Save button on the Bomb Control Panel to save data to
the lab book. Allow the graph to proceed for 20–30 seconds to establish a
baseline temperature.
5. Click Ignite and observe the graph. Observe the time in the Plot window.
When 4.5 minutes have passed, click the Save button in the Plot window to
save the graph. A blue link will appear in the lab book. Click the blue link to
open the saved graph window.
50
Energy of a Chemical Reaction
© Pearson Education, Inc. All rights reserved.
1. Start Virtual Physical Science and select Energy of a Chemical Reaction from
the list of assignments. The lab will open in the Calorimetry laboratory. A
disassembled bomb calorimeter is visible. A sample of chicken fat is in the
calorimeter cup on the balance. The balance has already been tared.
sx07CAGr8_VPhyLab_19.fm Page 51 Thursday, July 19, 2007 9:11 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
Use the graph in the Lab Book Plot window to answer the following questions.
1. Interpreting Graphs What was the temperature before igniting the
reaction?
__________________________________________________________________
What was the temperature after 2 minutes?
__________________________________________________________________
At what time was the temperature 26.50 °C?
__________________________________________________________________
2. Calculating By how many degrees did the temperature change from the
beginning of ignition until the time that the blue plot line ends?
__________________________________________________________________
3. Interpreting Data Is the combustion of chicken fat endothermic or
exothermic? Explain.
__________________________________________________________________
__________________________________________________________________
4. Drawing Conclusions Suppose that in another reaction, the temperature
in the bomb calorimeter decreased. What kind of reaction would have
occurred? Explain.
__________________________________________________________________
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
Energy of a Chemical
Reaction
Energy of a Chemical Reaction
51
sx07CAGr8_VPhyLab_20.fm Page 52 Thursday, August 9, 2007 7:03 AM
Name ___________________________
Date ___________________
Class ____________
Lab 20: Investigating the Properties of Alpha
and Beta Particles
Problem
To investigate the differences in charge and mass of alpha and beta particles
Background
As scientists began investigating the properties of atoms, they first discovered
that negatively charged particles could be extracted. Scientists called these
particles electrons. In the context of nuclear decay, however, electrons are
known as beta particles. Another particle ejected during nuclear decay is the
alpha particle. An alpha particle is a helium nucleus, or a helium atom without
its two electrons. Consequently, an alpha particle is positively charged. Ernest
Rutherford used alpha particles in his Gold Foil Experiment.
Skills Focus
Observing, drawing conclusions
Procedure
1. Start Virtual Physical Science. Select Investigating the Properties of Alpha and
Beta Particles from the list of assignments. The lab will open in the Quantum
laboratory.
2. Observing What source is used in this experiment? Drag your cursor over
the source to identify it.
What detector is used in this experiment?
__________________________________________________________________
3. Turn on the Phosphor Screen. (Click on the green/red button.)
What do you observe?
__________________________________________________________________
Investigating the Properties of
Alpha and Beta Particles
The phosphor screen detects charged particles (such as electrons) and it
glows momentarily at the positions where the particles impact the screen.
__________________________________________________________________
4. Drag the lab window down and left and the phosphor screen window up
and right in order to minimize the overlap. Push the Grid button on the
phosphor screen, and set the Magnetic Field to 30 µT. (Click the button above
the tens place three times. If you mistakenly click between digits, it will
move the decimal point. Click it to place it where it was originally and then
click above the tens place.)
What happens to the spot from the electron gun on the phosphor screen?
__________________________________________________________________
52
Investigating the Properties of Alpha and Beta Particles
© Pearson Education, Inc. All rights reserved.
What type of charge do electrons have?
__________________________________________________________________
sx07CAGr8_VPhyLab_20.fm Page 53 Thursday, August 9, 2007 7:02 AM
Name ___________________________
Date ___________________
Class ____________
5. Click once above the tens place on the Electric Field meter. Observe the spot.
Click a second time above the tens place on the Electric Field.
What happens to the spot from the electron gun on the phosphor screen?
__________________________________________________________________
6. Zero out the Magnetic Field and Electric Field meters by clicking on the
appropriate digit buttons until the spot on the phosphor screen is centered
again.
7. Double-click or click and drag the electron gun to move it to the Stockroom
counter. Enter the Stockroom by clicking inside the Stockroom. Double-click
the electron gun to move it back to the shelf. Double-click on the alpha
source to select it and move it to the Stockroom counter. Click on the green
Return to Lab arrow to return to the lab. Drag the alpha source from the
Stockroom counter and place it on the table where the electron gun was
originally placed (the middle spot light). Click on the front of the alpha
source to open the shutter.
What appears on the phosphor screen?
__________________________________________________________________
8. Change the unit for the Magnetic Field from µT to mT by clicking once above
the unit. Click above the hundreds place three times to set the Magnetic Field
to 300 mT (millitesla). This magnetic field is one million times stronger than
what we used for the electron gun.
Which direction is the spot deflected when the magnetic field is increased
this time?
__________________________________________________________________
9. Change the unit for the Electric Field from V to kV by clicking once above the
unit. Observe the spot as you increase the Electric Field strength from 0 kV to
5 kV. The movement is slight so pay careful attention.
How does this compare with the direction of movement for the electron
beam in the Electric Field?
__________________________________________________________________
Drawing Conclusions Why does it take significantly stronger magnetic and electric
field strengths to move the beam of alpha particles compared with the beam of
electrons (beta particles)?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Investigating the Properties of Alpha and Beta Particles
53
Investigating the Properties of
Alpha and Beta Particles
© Pearson Education, Inc. All rights reserved.
How does this compare with the direction of movement when the magnetic
field was turned on for the electrons?
__________________________________________________________________
sx07CAGr8_VPhyLab_21.fm Page 54 Thursday, July 19, 2007 9:12 AM
Name ___________________________
Date ___________________
Class ____________
Lab 21: Measuring Speed
Measuring Speed
Purpose
To calculate the speed of an object from measurements of distance and time
Background
How long does it take you to get to school in the morning? How long will it
take you to run a mile? These times depend on the average speed you can
travel. Speed is calculated from measurements of distance and time. In this
assignment, you will learn the relationship between distance and time for
moving objects. Then you will know how to calculate the average speed of
anything that moves.
Skills Focus
Graphing, predicting, interpreting data, applying concepts
Procedure
1. Start Virtual Physical Science. Select Measuring Speed from the list of
assignments. The lab will open in the Mechanics laboratory.
2. The laboratory is set up with a ball on a table. Attached to the ball is a
plunger used to hit the ball. You are going to measure the length of the table
and the time it takes the ball to roll across this distance. You will also record
the force you used to hit the ball and get it rolling.
__________________________________________________________________
__________________________________________________________________
3. The plunger is initially set to hit the ball with a force of 100 N. Measure the
distance (in centimeters) that the ball rolls on the table. Record this length in
Table 1. Start the ball rolling by clicking the Force button. When the ball hits
the edge of the screen, the experiment will stop. Record in Table 1 the time it
took the ball to roll across the table. You will find this time in the Time
display on the experiment screen. Repeat the experiment six times using
different force settings for the plunger. Click the Reset button. Change the
plunger force using the Parameters Palette. You can open the Palette by
clicking the Parameters button. In the Palette, click on the Forces tab to
change the force settings. Use some weaker and stronger forces. Record your
data in Table 1.
54
Measuring Speed
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One ball rolls across the full length of a table in a short time. Another ball
takes a long time to roll across the same table. How do the speeds of the two
balls compare?
__________________________________________________________________
sx07CAGr8_VPhyLab_21.fm Page 55 Thursday, August 9, 2007 7:04 AM
Name ___________________________
Date ___________________
Class ____________
Table 1
Force (N)
Distance of Roll (cm)
Time of Roll (s)
Measuring Speed
Analyze and Conclude
© Pearson Education, Inc. All rights reserved.
1. Graphing Plot the time and distance for the initial experiment on the
graph. Label the horizontal axis Time (s). Label the vertical axis Distance
(cm).You have two data points. The first data point will be (0 s, 0 cm). This is
the time and place the roll began. The second data point is the time and
distance you measured. You will need to scale the graph to fit your data.
2. On the same graph, plot a different line starting at point (0 s, 0 cm) for each
of the different forces you used. The second data point for each line is the
time and distance you measured and recorded in Table 1. You might use a
different colored pencil for each line. The lines you draw show that the ball
started in the same place and traveled the measured distance over a
different amount of time.
Measuring Speed
55
sx07CAGr8_VPhyLab_21.fm Page 56 Thursday, August 9, 2007 7:05 AM
Measuring Speed
Name ___________________________
Date ___________________
Class ____________
3. Each line should have a different steepness. This is called the slope of the
line. What does the slope of each line tell you about the ball as it rolled
across the table? Think back to what you observed in the different
experiments.
__________________________________________________________________
Predicting What would you predict for the slope of the line if another ball
took an even shorter amount of time to cross the table?
__________________________________________________________________
Predicting What would you predict for the slope of the line if another ball
took an even longer time to cross the table?
__________________________________________________________________
4. Interpreting Data You can calculate the slope of a line by using the
following equation.
slope = rise/run
In this experiment the rise is the distance the ball traveled. The run is the time it
took. Since rise is distance and the run is time, the slope = distance/time. Speed
tells you how long it took to go a measured distance, so if you go faster, it takes
less time. The slope of each line in your graph is the speed of the ball. From the
data on the graph or in Table 1, fill in Table 2 below and calculate the speed of
the ball.
Table 2
Distance (cm)
Time (s)
Speed (cm/s)
© Pearson Education, Inc. All rights reserved.
5. Applying Concepts On a trip, you measure the time it takes you to travel
between City A and City B. If you know the distance between the two cities,
how would you calculate the average speed of your trip?
__________________________________________________________________
__________________________________________________________________
56
Measuring Speed
sx07CAGr8_VPhyLab_22.fm Page 57 Thursday, August 9, 2007 7:06 AM
Name ___________________________
Date ___________________
Class ____________
Lab 22: Graphing Motion
Purpose
To learn how to use graphs to describe the motion of objects
Background
Line graphs are used to describe the motion of an object such as a rolling ball, a
moving automobile, or an airplane in flight. In this assignment, you will use
graphs to describe the motion of several rolling balls with different masses. By
analyzing the graphs, you will better understand the motion of the object.
Skills
Graphing, predicting, interpreting data, drawing conclusions
Procedure
Graphing Motion
1. Start Virtual Physical Science. Select Graphing Motion from the list of
assignments. The lab will open in the Mechanics laboratory.
2. The laboratory is set up with a 10-kg ball on a table. Attached to the ball is a
plunger to be used to hit the ball. You will hit the ball and observe it as it
rolls across the table. You will record the position of the ball over a period of
time in your electronic lab book. You will use your data to make a line graph
of the distance traveled versus time.
© Pearson Education, Inc. All rights reserved.
3. Click on the Lab Book to open it. Click on the red Recording button to start
recording data. Start the ball rolling by clicking on the Force button and wait
until the ball hits the end wall. You should see a link appear in the Lab Book.
This contains the position versus time data for the ball as it rolls across the
table.
4. Click on the data link in your lab book to view the position of the ball throughout
the time of the experiment. Record in the table below the positions of the ball at
the indicated times. Click the Reset button. Repeat the experiment with a slightly
larger mass, and then a slightly smaller mass. Change the mass using the Objects
tab under the Parameters Palette.
Mass:
Time
(sec)
Mass:
Position
(m)
Time
(sec)
Mass:
Position
(m)
Time
(sec)
0
0
0
1
1
1
2
2
2
3
3
3
4
4
4
5
5
5
6
6
6
Position
(m)
Graphing Motion
57
sx07CAGr8_VPhyLab_22.fm Page 58 Thursday, August 9, 2007 7:08 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
Graphing Motion
1. Graphing Use data from the data table to graph the motion of the three
balls. Your graph should show the distance the ball traveled versus the time,
so time is shown on the horizontal or x-axis and distance is shown on the
vertical or y-axis. Label the axes with the variable and its units. Use a
different colored pencil to connect the points for each ball. You will need to
scale the graph to fit your data.
__________________________________________________________________
3. What is the difference between the three lines you graphed?
__________________________________________________________________
__________________________________________________________________
4. The steepness of the line is called the slope of the line. The slope is how far
the data goes up on the y-axis (the rise) divided by how far the data goes out
on the x-axis (the run). What do the slopes of the lines tell you about each
ball?
__________________________________________________________________
__________________________________________________________________
58
Graphing Motion
© Pearson Education, Inc. All rights reserved.
2. Interpreting Graphs What does each point on the graph represent?
__________________________________________________________________
sx07CAGr8_VPhyLab_22.fm Page 59 Thursday, July 19, 2007 9:13 AM
Name ___________________________
Date ___________________
Class ____________
5. The graph below shows the motion of a dog. Describe the motion of the dog.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Time
80
70
60
40
Graphing Motion
Distance
50
30
20
10
0
0
2
4
6
8
10
6. How does the graph show that the dog had different speeds in the first four
seconds and the last two seconds?
__________________________________________________________________
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
__________________________________________________________________
__________________________________________________________________
Graphing Motion
59
sx07CAGr8_VPhyLab_23.fm Page 60 Thursday, July 19, 2007 9:14 AM
Name ___________________________
Date ___________________
Class ____________
Lab 23: Acceleration
Problem
To study the acceleration of a ball when it is thrown straight up into the air
Background
You experience acceleration when you walk faster to get somewhere on time,
or slow down to talk to a friend, or turn a corner as you walk down the hall.
What do these movements have in common? They are examples of a change in
speed or a change in direction. A change in the speed or direction of a moving
object is acceleration. Acceleration can be positive (speeding up) or negative
(slowing down). Negative acceleration is sometimes called deceleration.
Skills Focus
Predicting, observing, graphing, interpreting data, drawing conclusions
Procedure
1. Start Virtual Physical Science. Select Acceleration from the list of assignments.
The lab will open in the Mechanics laboratory.
2. The laboratory is set up with a ball near the bottom of the experiment
window. A plunger is attached to the bottom of the ball. The ball will be shot
straight up into the air by the plunger, but there will be gravity to pull it
back down. You will observe the acceleration of the ball as it rises in the air
and then falls back to the bottom of the screen.
Acceleration
__________________________________________________________________
3. Click on the Lab Book to open it. Click on the red Recording button to start
recording data. Hit the ball into the air by clicking on the Force button.
Observe the trajectory or path of the ball. The force of the plunger is initially
set to hit the ball with a force of 200 newtons (N). When the ball reaches the
bottom, the experiment will stop. You should see a link appear in the Lab
Book. This contains the position versus time data and the velocity versus
time data for the ball flying through the air. If you click on the data link, the
Data Viewer window will open with three columns of data. The first
column, t (sec), is Time. The second column, y (m), gives the Position of the
ball. The third column, v_y (m/s), gives the Velocity.
60
Acceleration
© Pearson Education, Inc. All rights reserved.
Predicting How will the speed of the ball change as it moves up in the air?
How will the speed change as the ball falls back down?
__________________________________________________________________
sx07CAGr8_VPhyLab_23.fm Page 61 Thursday, July 19, 2007 9:14 AM
Name ___________________________
Date ___________________
Class ____________
4. Try the experiment again with different forces on the plunger. Click the Reset
button to reset the experiment. Click the Parameters button. Change the force
in the Parameters Palette to a different value by clicking the Forces tab in the
Palette and repeat Step 3. Hit the ball with two different forces. Use larger
and smaller forces.
Observing In each of these experiments where, along its path, does the
ball accelerate?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Analyze and Conclude
1. Graphing Use the data in each of the data links in your Lab Book to draw
the position versus time graphs on the grid below. Label the horizontal axis
Time (s) and the vertical axis Position (m). You will need to scale the graph
to fit your data. Use about 10 points from each data link to describe the
trajectory of the ball. The first data point in each graph is (0 m, 0 s). This is
the time and place where the ball was hit. You will be plotting the height of
the ball (the y data) over the time period of the whole trajectory of rising and
falling. Use a different colored pencil for each experiment. Connect the data
points with lines. Note: Ignore all data in which the ball’s position is
negative.
© Pearson Education, Inc. All rights reserved.
Acceleration
Acceleration
61
sx07CAGr8_VPhyLab_23.fm Page 62 Friday, August 10, 2007 12:40 PM
Name ___________________________
Date ___________________
Class ____________
3. Interpreting Data How do the velocity versus time graphs show that the
balls are accelerating?
__________________________________________________________________
__________________________________________________________________
4. What does the negative slope of the velocity graph above the horizontal axis
mean? What does the negative slope of the velocity graph below the
horizontal axis mean?
__________________________________________________________________
__________________________________________________________________
5. Drawing Conclusions Is there a relationship between the slopes of the
lines and the plunger forces? Hint: Does the size of the force used to hit the
ball have anything to do with the velocity when the ball was falling? What
about the velocity when the ball was rising?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
62
Acceleration
© Pearson Education, Inc. All rights reserved.
Acceleration
2. After you have made your graphs of position versus time, select the velocity
versus time data from the data link. Graph velocity versus time on the grid
below. Label the horizontal axis Time (s) and the vertical axis Velocity (m/s).
Use about 10 data points to describe the trajectory of the balls. Connect the
points. Use the same colors or line styles for the same experiments as you
did for the first graph. Label each line with the plunger force. Identify the
parts of the trajectory where the speed is increasing, where the speed is
decreasing, and where the ball is changing direction. (Hint: Choose equal
amounts between the intervals.)
sx07CAGr8_VPhyLab_24.fm Page 63 Thursday, July 19, 2007 9:15 AM
Name ___________________________
Date ___________________
Class ____________
Lab 24: Forces
Purpose
To understand the effects of balanced and unbalanced forces on an object
Background
Have you ever played tug of war or arm wrestled with a friend? To win, you
must use a force greater than that of your opponent. If the force you use is
equal to the force of your opponent, the opposing forces are balanced and the
net force is zero. Nobody wins. When the net force, or sum of the forces, is not
equal to zero, the forces are unbalanced. Unbalanced forces cause objects to
move, stop moving, or change direction. You can predict the motion of objects
by looking at the net forces acting on them. In this assignment you will watch
balls being acted on by forces and determine whether the net force is balanced
or unbalanced.
Skills Focus
Observing, controlling variables, applying concepts
Procedure
1. Start Virtual Physical Science. Select Forces from the list of assignments. The
lab will open in the Mechanics laboratory.
2. The laboratory is set up with a ball at the top of the experiment window.
Attached to the bottom of the ball is a rocket to push (force) the ball up. In
this experiment, gravity has been turned on. Gravity will tend to pull the
ball down. The object in this experiment is to apply just the right amount of
force with the rocket to keep the ball from going up or from falling.
Observing What did you observe when you turned on the rocket?
__________________________________________________________________
4. Now experiment to determine the amount of force needed to balance the
ball. Click the Reset button to go back to the beginning of the experiment.
Use the Forces tab in the Parameters Palette to change the rocket force and
repeat Step 3. Observe whether the ball falls or goes up. Record each force
you try and your observations in Table 1. Continue until you can keep the
ball from either falling or rising.
Why do you need to change the rocket’s force?
__________________________________________________________________
Forces
© Pearson Education, Inc. All rights reserved.
3. Start the experiment by clicking on the Start button. Observe what happens.
To turn on the rocket, click on the Force button. When you are done with
your observations, click the Pause button to stop the experiment.
__________________________________________________________________
Forces
63
sx07CAGr8_VPhyLab_24.fm Page 64 Thursday, July 19, 2007 9:15 AM
Name ___________________________
Date ___________________
Class ____________
Table 1
Force (N)
Observations
Balanced/Unbalanced
5. Controlling Variables Now find out what happens to the motion of the
ball when the rocket is attached to the ball at a different position. Reset the
experiment to the beginning by clicking on the Reset button. Using the
Parameters Palette, set the angle of the rocket to 270°and set the force to
200 N. Record your observations in Table 2. Now repeat the experiment
using angles of 0°, 180°, and an angle of your choice. Record your results in
Table 2.
Table 2
Force (N)
270°
200
0˚
200
180˚
200
Effect on the
Ball
Balanced/Unbalanced
200
Analyze and Conclude
1. What is the difference between the forces used in Table 1 and those in Table 2?
__________________________________________________________________
__________________________________________________________________
2. How do balanced forces affect the ball?
__________________________________________________________________
3. How do unbalanced forces affect the ball?
__________________________________________________________________
Forces
4. Applying Concepts Why would it be important to understand the concept
of net force when trying to build a rocket to travel to the moon?
__________________________________________________________________
__________________________________________________________________
64
Forces
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Angle
sx07CAGr8_VPhyLab_25.fm Page 65 Thursday, August 9, 2007 7:33 AM
Name ___________________________
Date ___________________
Class ____________
Lab 25: Measuring Friction:
A Sticky Topic
Measuring Friction:
A Sticky Topic
Problem
To discover how friction affects the motion of a sliding object
Background
Friction is a force that acts in the opposite direction of motion. A car moves
because of the friction between its tires and the ground. Walking is usually easy
because your feet slightly stick to the ground or floor. As you walk forward,
your foot pushes backwards. Because of friction your feet don’t slide out from
under you unless you are on ice. In this lab you will discover the effects of
different surfaces and materials on the time it takes for friction to stop a sliding
sled.
Skills Focus
Interpreting data, predicting, drawing conclusions, applying concepts
Procedure
1. Start Virtual Physical Science. Select Measuring Friction from the list of
assignments. The lab will open in the Mechanics laboratory.
2. The laboratory is set up with a sled, or block, on a table. A plunger is
attached to start the sled moving. Notice that the table is made of cement
and the sled is made of wood. You will hit the sled and watch it slide across
the table.
Note that the mass of the sled is 1 kg. What is the weight of the sled in
newtons?
© Pearson Education, Inc. All rights reserved.
Remember Weight = Mass Acceleration due to gravity.
__________________________________________________________________
Predicting Would it be easier to push this rubber sled or a metal sled?
__________________________________________________________________
__________________________________________________________________
3. Click on the Lab Book to open it. Click the Record button to start recording
data. Start the sled sliding on the table by clicking on the Force button.
Observe what happens. The plunger hit the sled with a force of 225 newtons.
As soon as the sled stops moving, click the Stop button to stop the
experiment. Click the Stop button to stop recording data. You should see a
link appear in the lab book. This contains the position versus time data of
the sled sliding on the table. Use this data to record in the table below the
distance the sled traveled and the time it took the sled to stop.
Measuring Friction: A Sticky Topic
65
sx07CAGr8_VPhyLab_25.fm Page 66 Thursday, August 9, 2007 7:33 AM
Measuring Friction:
A Sticky Topic
Name ___________________________
Date ___________________
Class ____________
4. Try other types of materials for the sled and the table to see how changes in
friction affect the sled’s stopping time. Click the Reset button to reset the
experiment before trying new materials. Choose different materials in the
Parameters Palette under the Frictions tab. The sled’s appearance will not
change. For each trial record in the table below the materials of the sled and
the table, the distance the sled travels until it stops, and the time it takes
to stop.
Table
Material of the
Sled
Material of the
Table
Wood
Cement
Sliding
Distance (m)
Sliding Time
(s)
Analyze and Conclude
2. Interpreting Data With what materials did the sled slide longest? With
what materials did the sled stop fastest? Why?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
3. Predicting What would happen if you repeated the experiment using a
heavier sled?
__________________________________________________________________
4. Drawing Conclusions Describe how the amount of friction between an
object and a surface determines the amount of force needed to move the
object.
__________________________________________________________________
5. Applying Concepts If you were designing an automobile tire, would you
want to have a lot of friction (very sticky and rough), not a lot of friction
(very smooth), or somewhere in between? Why?
66
Measuring Friction: A Sticky Topic
© Pearson Education, Inc. All rights reserved.
1. What stops the sled from moving?
__________________________________________________________________
sx07CAGr8_VPhyLab_26.fm Page 67 Thursday, August 9, 2007 7:34 AM
Name ___________________________
Date ___________________
Class ____________
Lab 26: Acceleration and Friction
Purpose
To investigate the effect that friction has on the acceleration of an object
Background
Have you ever tried to ride a bike with flat tires, or push a heavy crate across a
rough floor? Chances are you couldn’t get the bike or the crate to move very
fast. What makes these activities so hard is the large amount of friction
involved. In this assignment, you will look at the effect of friction on the
acceleration of an object.
Skills Focus
Graphing, interpreting data, drawing conclusions
Acceleration and Friction
Procedure
1. Start Virtual Physical Science. Select Acceleration and Friction from the list of
assignments. The lab will open in the Mechanics laboratory.
2. The laboratory is set up with a sled on a table. The surface of the table can be
covered with different kinds of sandpaper. Attached to the sled is a small
rocket that will be used to push the sled. Click on the Lab Book to open it.
3. In the first experiment, the friction coefficient will be set at 0.1. Click on the
red Recording button to save the position versus time data. Click on the Force
button to start moving the sled. The rocket should turn off automatically
after two seconds. When the sled has stopped moving, click on the Pause
button to stop the experiment and stop recording data. A new data link
should appear in your Lab Book. Click the Reset button to reset the
experiment.
© Pearson Education, Inc. All rights reserved.
4. Repeat Step 3 five more times using coefficients of friction of 0.2, 0.3, 0.4, 0.5,
and 0.6. Use the Frictions tab in the Parameters Palette to change the friction.
The table below summarizes the different conditions for the experiments.
Table
Initial
Position
(m)
Force
(N)
Coefficient
of Friction
0
10
0.1
0
10
0.2
0
10
0.3
0
10
0.4
0
10
0.5
0
10
0.6
Acceleration and Friction
67
sx07CAGr8_VPhyLab_26.fm Page 68 Thursday, July 19, 2007 9:16 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
Acceleration and Friction
1. Graphing On the grids below, graph the position versus time for each of
the six different experiments. Graph the first three experiments on the top
grid and the other three on the bottom grid. Use the data found in the data
links saved in your Lab Book. Label the horizontal axis Time (s). Label the
vertical axis Distance (m). Use a different colored pencil for each graph. You
will need to scale the graphs to fit your data.
© Pearson Education, Inc. All rights reserved.
68
Acceleration and Friction
sx07CAGr8_VPhyLab_26.fm Page 69 Thursday, July 19, 2007 9:16 AM
Name ___________________________
Date ___________________
Class ____________
2. Identify on the graphs the place where the rocket finished firing. Do this for
each data run.
3. Interpreting Data As the friction increases, what happens to the shape of
the position versus time graphs during the firing interval? Explain why.
__________________________________________________________________
__________________________________________________________________
4. What happens to the shapes of the position versus time graphs after the
rockets turn off?
__________________________________________________________________
5. How does the frictional force affect the acceleration of the sled? How does
the rocket force affect the acceleration of the sled?
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
Acceleration and Friction
__________________________________________________________________
Acceleration and Friction
69
sx07CAGr8_VPhyLab_27.fm Page 70 Thursday, August 9, 2007 7:36 AM
Name ___________________________
Date ___________________
Class ____________
Lab 27: Gravity and Free Fall Motion
Purpose
To find out what effect air resistance has on a falling object
Background
When an object falls through the air, two forces act on it. The force of gravity
pulls the object down and the force of air resistance slows the object’s fall by
opposing the motion. Air resistance is an example of fluid friction, which
applies an opposing force through a gas or liquid. When you stick your hand
out the window of a moving car, you can feel the air resistance against your
hand. As the car goes faster, the air resistance increases. If you have jumped
into a pool, you have felt the resistance of water, which slows you down much
faster than air does. In this assignment, you will observe the effects of air
resistance on the acceleration of falling objects.
Skills Focus
Graphing, intepreting data, drawing conclusions
Procedure
2. The laboratory is set up with a ball at the top of the experiment window,
20 m above the surface. Gravity is set at the same value as on Earth. Gravity
will pull the ball down. You will observe how long it takes the ball to reach
y = 0. The mass of the ball is 2 kg. The diameter of the ball is 1 m.
3. Click on the Lab Book to open it. Click on the red Recording button to start
recording data. Start the experiment by clicking on the Start button and
observe what happens. When the ball reaches y = 0, the experiment will
stop. You should see a link appear in the Lab Book. This contains the velocity
versus time data for the ball falling. In the table on the next page, write the
amount of time it took the ball to fall and its velocity at the nearest data
point to when the ball crosses y = 0.
4. Click the Reset button to reset the experiment. Place the air resistance
graphic from the tray onto the work area. Repeat Step 3 to record the
velocity of the ball as it falls.
5. Drop another ball with the same mass as before but a much larger diameter
(for example, a large hollow ball). Click the Reset button to reset the
experiment. Use the Objects tab in the Parameters Palette to adjust the radius
to 4 m. Repeat Step 3.
70
Gravity and Free Fall Motion
© Pearson Education, Inc. All rights reserved.
Gravity and Free Fall Motion
1. Start Virtual Physical Science. Select Gravity and Free Fall Motion from the list
of assignments. The lab will open in the Mechanics laboratory.
sx07CAGr8_VPhyLab_27.fm Page 71 Thursday, August 9, 2007 7:36 AM
Name ___________________________
Date ___________________
Class ____________
6. Click the Reset button again. Use the Parameters Palette to adjust the radius to
4 m again, but this time, place the air resistance graphic back on the table
from the tray. Repeat Step 3 to record the velocity of the ball as it falls.
Mass
of Ball
(kg)
Diameter
(m)
Air Resistance
(on or off?)
2
1
off
2
1
on
2
4
off
2
4
on
Time to Reach
y 0 (s)
Velocity at
y 0 (m/s)
Analyze and Conclude
Gravity and Free Fall Motion
© Pearson Education, Inc. All rights reserved.
1. Graphing Using the data in each of the data links in the Lab Book, draw the
velocity versus time graphs for each experiment on the grid below. Label the
horizontal axis Time (s) and the vertical axis Velocity (m/s). Scale your graph
to fit your data. The first data point is (0 s, 0 m/s) for each experiment.
Connect the data points using a different colored pencil for each graph. Label
each line with the radius of the ball and indicate if there was air resistance.
2. Interpreting Data Describe any differences you see in the graphs. Explain
why the graphs are different. Is there a difference in the motion of the objects
with or without air resistance?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Gravity and Free Fall Motion
71
sx07CAGr8_VPhyLab_27.fm Page 72 Thursday, July 19, 2007 9:16 AM
Name ___________________________
Date ___________________
Class ____________
3. Interpreting Data Why do two of the graphs look exactly the same?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
4. Interpreting Data Do the graphs of experiments with air resistance have
any regions that show constant acceleration? Do they have any regions with
constant velocity, or no acceleration? Why wouldn’t the balls accelerate even
with gravity still pulling them down? What is stopping them?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
5. Drawing Conclusions The point at which a falling object stops
accelerating is called the terminal velocity. Why is terminal velocity an
appropriate name?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
6. How would the motion of the balls change if you increased the force of
gravity with air resistance on?
__________________________________________________________________
__________________________________________________________________
72
Gravity and Free Fall Motion
© Pearson Education, Inc. All rights reserved.
Gravity and Free Fall Motion
Going Further
sx07CAGr8_VPhyLab_28.fm Page 73 Thursday, July 19, 2007 9:17 AM
Name ___________________________
Date ___________________
Class ____________
Lab 28: Newton’s First Law
Purpose
To discover how mass and inertia are related
Background
Motion surrounds you in your everyday life. Scientists have been fascinated by
it for thousands of years. Sir Isaac Newton proposed three laws to describe
motion. Newton’s first law of motion states that an object at rest will remain at
rest, and an object moving at a constant velocity will continue moving at a
constant velocity, unless it is acted on by an outside force. This is also called the
law of inertia. In this assignment you will measure the distance it takes a force
to stop the motion of balls of different masses. The data you collect will provide
a measure of the inertia of different objects and their tendency to resist change.
Skills Focus
Graphing, predicting, interpreting data, drawing conclusions, controlling
variables
Procedure
1. Start Virtual Physical Science. Select Newton’s First Law from the list of
assignments. The lab will open in the Mechanics laboratory.
3. After a couple of seconds, press the Force button to turn on the rocket. The
Force is set to 10 N. Click the Pause button when the ball slows down and
starts to reverse direction. You should see a link appear in the Lab Book. This
contains the position versus time data and the velocity versus time data of
the ball rolling across the table.
4. Use the data collected to fill out the table below with (1) the magnitude of
the force, (2) the distance the ball traveled from when the force was turned
on to when it stopped and reversed direction, and (3) the amount of time the
force was on. Find in the data the time when the velocity is decreasing, but
is still positive, showing that the ball is still traveling to the right, but the
force is acting on the ball. You can find the distance traveled and the time
from this part of the data.
Newton’s First Law
Newton’s First Law
© Pearson Education, Inc. All rights reserved.
2. The laboratory is set up with a 2-kg ball on a table. Attached to the ball is a
rocket used to push the ball in the direction opposite to the motion of the
ball. The ball will have an initial velocity. There is no friction. The only thing
stopping the ball is the force you turn on. Click on the Lab Book to open it.
Click on the red Recording button to start recording data. Start the ball
rolling across the table by clicking on the Start button.
73
sx07CAGr8_VPhyLab_28.fm Page 74 Thursday, July 19, 2007 9:17 AM
Name ___________________________
Date ___________________
Class ____________
5. Controlling Variables Repeat the experiment with balls of three different
masses. Remember to click the Reset button before choosing each new mass.
Use the Objects tab under the Parameter Palette to change the mass of the ball.
Keep the force the same for all of the experiments. The time the rocket is on
will be different for each ball, because all the balls will stop in different
amounts of time.
Table
Mass of Ball
(kg)
Force
Applied to
Ball (N)
Distance
Traveled After
Rocket Was
Turned On (m)
Time Rocket Is
On (s)
Analyze and Conclude
Newton’s First Law
74
Newton’s First Law
© Pearson Education, Inc. All rights reserved.
1. Graphing On the grid below, graph the distance versus time for each of
the four experiments. Use the data in the data links saved in your Lab Book.
Label the horizontal axis as Time (s) and the vertical axis as Distance (m).
Decide on the proper scaling for the axes. Use a different colored pencil for
each graph. Label the point at which the rocket was turned on in each
experiment.
sx07CAGr8_VPhyLab_28.fm Page 75 Thursday, July 19, 2007 9:17 AM
Name ___________________________
Date ___________________
Class ____________
2. Interpreting Data Which mass was easiest to stop? Which was hardest?
How do you know?
__________________________________________________________________
__________________________________________________________________
3. Predicting What would happen if you had a smaller force pushing on the
same balls? Would they still stop? Hint: The balls have initial velocity but
what is actually making the balls stop?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
4. Making Generalizations You have worked with rocket forces in this lab,
but what other types of forces do you think would change the motion of the
ball?
__________________________________________________________________
__________________________________________________________________
5. Drawing Conclusions What would happen if you increased the mass of
the ball but didn’t apply any force?
__________________________________________________________________
__________________________________________________________________
What is the relationship between the mass of an object and its inertia or
resistance to motion?
__________________________________________________________________
Newton’s First Law
© Pearson Education, Inc. All rights reserved.
__________________________________________________________________
Newton’s First Law
75
sx07CAGr8_VPhyLab_29.fm Page 76 Thursday, July 19, 2007 9:17 AM
Name ___________________________
Date ___________________
Class ____________
Lab 29: Newton’s Second Law
Newton’s Second Law
Purpose
To investigate how force and mass affect the acceleration of an object
Background
Newton’s second law of motion states that the acceleration of an object
depends on the object’s mass and the net force applied to the object. The law
can be written mathematically as Force Mass Acceleration or F m a.
This equation can also be rearranged.
Acceleration Force
-------------Mass
Skills Focus
Graphing, predicting, interpreting graphs, controlling variables, drawing
conclusions
Procedure
1. Start Virtual Physical Science. Select Newton’s Second Law from the list of
assignments. The lab will open in the Mechanics laboratory.
Predicting What do you think your velocity versus time graphs will look
like if the ball is accelerating?
__________________________________________________________________
3. Click on the Lab Book to open it. Click on the red Recording button to start
recording data. Start the ball rolling by clicking on the Force button. Observe
what happens as the ball rolls across the table. The force is set to 10 N and
the mass of the ball is 1 kg. Does the ball speed up? The ball will stop when
it reaches the end of the table. You should see a link appear in the Lab Book
containing the position versus time and velocity versus time data of the ball
rolling across the table.
4. Click the Reset button to reset the experiment back to the beginning. Use the
Forces tab under the Parameters Palette to change the rocket force and repeat
Step 3 for two different forces. Record the forces in the table below.
76
Newton’s Second Law
© Pearson Education, Inc. All rights reserved.
2. The laboratory is set up with a ball on a table. Attached to the ball is a rocket
used to push the ball across the table. There is no friction. In this experiment,
you will collect position and velocity data as the ball moves across the table.
Then you will make position and velocity graphs.
sx07CAGr8_VPhyLab_29.fm Page 77 Thursday, July 19, 2007 9:17 AM
Name ___________________________
Date ___________________
Class ____________
Newton’s Second Law
5. Now observe what happens to the ball’s speed and acceleration when you
change the mass. Click the Reset button to reset the experiment back to the
beginning. Use the Objects tab under the Parameters Palette to change the
mass of the ball. Make sure the force is set to 10 N, and repeat Step 3 for two
different masses. Don’t change the force for these experiments. Record the
masses in the table.
Table
Force (N)
Mass of Ball
(kg)
10
1
Color of Line
on Graph
1
1
10
10
Analyze and Conclude
© Pearson Education, Inc. All rights reserved.
1. Graphing Using the data in each of the data links in your Lab Book, draw
the position versus time graphs on the grid below. You will be plotting the
distance of the ball versus the time as the ball crossed the table. Label the
horizontal axis as Time (s) and the vertical axis as Distance (m). Choose a
scale for your graph that fits your data. The first data point will be (0 s, 0 cm).
This is the time and position of the ball when it started rolling. Plot ten
points for each ball. Connect the data points using a different colored pencil
for each experiment. In the table above, write down the color of the line you
draw for each set of data.
Newton’s Second Law
77
sx07CAGr8_VPhyLab_29.fm Page 78 Thursday, July 19, 2007 9:17 AM
Newton’s Second Law
Name ___________________________
Date ___________________
Class ____________
2. Now select the velocity versus time data from your data links and graph
velocity versus time on the grid below. Label the horizontal axis Time (s)
and the vertical axis Velocity (m/s). Label each line with the force and mass
of the ball. Use the same colors for the graphs with the same masses and
forces.
__________________________________________________________________
How do the velocity versus time graphs show that the balls are accelerating?
__________________________________________________________________
__________________________________________________________________
Which ball accelerated the most?
__________________________________________________________________
4. Controlling Variables Explain how you could produce a large
acceleration using a very small force.
__________________________________________________________________
5. Drawing Conclusions What are two ways in which you can increase
acceleration?
__________________________________________________________________
78
Newton’s Second Law
© Pearson Education, Inc. All rights reserved.
3. Interpreting Graphs How do the position versus time graphs show that
the balls are accelerating?
__________________________________________________________________
sx07CAGr8_VPhyLab_30.fm Page 79 Thursday, July 19, 2007 9:18 AM
Name ___________________________
Date ___________________
Class ____________
Lab 30: Newton’s Third Law
Purpose
To study action and reaction by observing collisions between moving balls
Background
In the past, cannons were an important weapon for reaching the enemy at a
distance. However, soldiers had to be careful not to stand behind a cannon
when it was fired. The heavy cannon would “kick” back or roll backward with
each shot. This “kick” back is an example of Newton’s third law of motion: For
every action (the cannon ball firing forward at high speed) there is an equal and
opposite reaction (the cannon moving backwards at low speed). In this
assignment, you will observe the effects of reaction forces when balls of
different masses collide.
Skills Focus
Newton’s Third Law
Predicting, interpreting data, applying concepts, drawing conclusions
Procedure
1. Start Virtual Physical Science. Select Newton’s Third Law from the list of
assignments. The lab will open in the Mechanics laboratory.
2. The laboratory is set up with two balls of the same mass on a table. The balls
will move towards each other. As they collide they will exert forces on each
other which are equal and opposite.
Predicting When a more massive ball hits a less massive ball, how do the
forces they exert on each other compare? What is the resulting motion of the
balls?
__________________________________________________________________
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
__________________________________________________________________
3. The initial velocity of all of the balls will be the same for each trial, but the
masses of the balls will change. You will observe what happens in the
collisions and record the final velocities of each ball.
4. Click the Start button to start the balls in motion. After the balls bounce off
each other and move a short distance away from each other, click the Pause
button to stop the experiment. Note the velocity of each ball in the display
panel below the table. The display panel is set to show the values for Ball 1.
You can switch the values to Ball 2 by clicking on the arrows below Tracking
on the lower right. Record the velocities in the table. Describe what
happened to each ball in the reaction box.
5. Click the Reset button to reset the experiment before trying new masses. Use
the table to keep track of what mass to use for each trial. Use the Objects tab
under the Parameters Palette to change the mass of the balls. Make sure to
Newton’s Third Law
79
sx07CAGr8_VPhyLab_30.fm Page 80 Thursday, July 19, 2007 9:18 AM
Name ___________________________
Date ___________________
Class ____________
uncheck the box that reads “Balls Same Mass and Diameter” so you can try
balls of different masses. Set a negative velocity (moving to the left) by
adjusting the angle of the velocity to 180 degrees.
Table
Velocity
Before
Trial 1
Mass (kg)
Ball 1
10
10
Ball 2
10
10
Ball 1
20
10
Ball 2
10
10
Ball 1
50
10
Ball 2
1
10
Ball 1
1
10
Ball 2
50
10
Velocity
After
Reaction
Trial 2
Newton’s Third Law
Trial 3
Trial 4
Analyze and Conclude
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
2. Applying Concepts Explain why a lighter ball has more velocity after a
collision with a heavy ball than it had before. Where did that velocity come
from? Hint: Think about Newton’s second law.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
3. Drawing Conclusions Does the data prove your earlier prediction?
Explain.
__________________________________________________________________
4. Drawing Conclusions Why don’t the forces of action and reaction cancel
each other? Why isn’t the net force zero if the forces are the same in each
direction?
__________________________________________________________________
80
Newton’s Third Law
© Pearson Education, Inc. All rights reserved.
1. Interpreting Data Describe what happened when the masses of the balls
were the same, and when they were very different.
__________________________________________________________________
sx07CAGr8_VPhyLab_31.fm Page 81 Friday, August 17, 2007 6:56 AM
Name ___________________________
Date ___________________
Class ____________
Lab 31: Conservation of Momentum
Purpose
To discover what happens to the total momentum when objects collide
Background
You might think of conservation as paying attention to how much water or gas
you use. But conservation also means that conditions before and after an event
do not change. Conservation of momentum means that the total momentum of
any group of objects before an event is the same as it is afterwards. No
momentum has been lost and none has been gained. In this assignment you
will observe a system of two balls colliding. You will measure the momentum
before and after the collision and see if the two measurements are the same.
Skills Focus
Interpreting data, drawing conclusions, applying concepts
Procedure
1. Start Virtual Physical Science. Select Conservation of Momentum from the list
of assignments. The lab will open in the Mechanics laboratory.
2. The laboratory is set up with two balls of the same mass on a table. You will
perform three experiments to measure the momentum of the system by
measuring the momentum of each ball within the system.
© Pearson Education, Inc. All rights reserved.
Conservation of Momentum
3. Experiment 1: Two balls moving The masses of the balls are the same. The
velocities of the balls are the also the same in magnitude (size) but they are
not the same in direction. (The balls will be heading towards each other.)
The balls start out separated by 10 meters. Click the Start button to watch
them collide. Click the Pause button immediately after they bounce off each
other. Record the final velocity of each ball in Table 1 using the data in the
display panel in the experiment window. You will need to click the arrows
under Tracking to change the values in the panel from Ball 1 to Ball 2.
Table 1
Trial 1
Mass (kg)
Velocity
Before
(m/s)
Ball 1
10
–10
Ball 2
10
10
Velocity
After
(m/s)
Momentum
Before
(mass x
velocitybefore)
Momentum
After
(mass x
velocityafter)
Total Momentum =
Conservation of Momentum
81
sx07CAGr8_VPhyLab_31.fm Page 82 Friday, August 10, 2007 12:41 PM
Name ___________________________
Date ___________________
Class ____________
4. Experiment 2: One ball moving Click the Reset button to reset the
experiment. Use the Objects tab under the Parameters Palette to change the
mass of Ball 1 to 15 kg and the mass of Ball 2 to 5 kg. (First uncheck “Balls
Same Mass and Diameter.”) Set the velocity of Ball 1 to –10 m/s and the
velocity of Ball 2 to 0 m/s. Set a negative velocity (moving to the left) by
adjusting the angle of the velocity to 180 degrees. Click the Start button to
watch the balls collide. Click the Pause button immediately after they bounce
off each other and before ball 2 hits the wall. Record the final velocity of each
ball in Table 2 using the data in the display panel in the experiment window.
Table 2
Trial 2
Mass (kg)
Velocity
Before
(m/s)
Ball 1
15
–10
Ball 2
10
0
Velocity
After
(m/s)
Momentum
Before
(mass x
velocitybefore)
Momentum
After
(mass x
velocityafter)
Total Momentum =
5. Experiment 3: Choose your own variables Click the Reset button to reset
the experiment. Choose your own masses and velocities for each ball. Then
predict what you think the resulting velocities might be after the collision.
Test your prediction. Record the data in Table 3.
Trial 3
Mass
(kg)
Velocity
Before
(m/s)
Prediction:
Velocity
After (m/s)
Actual:
Velocity
After
(m/s)
Ball 1
Ball 2
Total Momentum =
82
Conservation of Momentum
Momentum
Before
(mass x
velocitybefore)
Momentum
After
(mass x
velocityafter)
© Pearson Education, Inc. All rights reserved.
Conservation of Momentum
Table 3
sx07CAGr8_VPhyLab_31.fm Page 83 Thursday, August 9, 2007 7:38 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
1. Interpreting Data Is the momentum of the system conserved in each trial?
Explain.
__________________________________________________________________
__________________________________________________________________
2. Applying Concepts If the balls were initially traveling along the same line
and in the same direction, would they also obey the law of conservation of
momentum? Try it out with Ball 1 going twice as fast as Ball 2 but both
heading to the right with some positive velocity. In the Parameters Palette, set
the angle of the velocity to be the same for both balls (Angle of 0°). Was there
anything that surprised you about this collision?
__________________________________________________________________
__________________________________________________________________
3. Drawing Conclusions How can a ball with a small mass have the same
momentum as a ball with a large mass?
__________________________________________________________________
4. Describe momentum in your own words.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
Conservation of Momentum
Conservation of Momentum
83
sx07CAGr8_VPhyLab_32.fm Page 84 Thursday, August 9, 2007 7:42 AM
Name ___________________________
Date ___________________
Class ____________
Lab 32: Floating Objects
Purpose
To determine the buoyant force
Background
Water and other fluids exert an upward force called the buoyant force that acts
on a submerged object. The buoyant force acts in the direction opposite to the
force of gravity, so it makes an object feel lighter. All objects take up space. A
submerged object displaces, or takes the place of, a volume of fluid equal to its
own volume.
Archimedes, a mathematician of ancient Greece, discovered a connection
between the weight of a fluid displaced by an object and the buoyant force
acting on it. Archimedes’ principle states that the buoyant force acting on a
submerged object is equal to the weight of the fluid the object displaces.
Skills Focus
Calculating, problem solving, drawing conclusions, and relating cause and
effect
Procedure
1. Start Virtual Physical Science. Select Floating Objects from the list of
assignments. The lab will open in the Density laboratory.
Determining Density
3. Click on the graduated cylinder to see a zoomed-in view of the level of the
fluid. Record the initial volume of the fluid in Table 1. Place the beaker on
the counter next to the cylinders on the balance and record the mass in Table
1. Drag the beaker back to the spotlight on the counter.
Floating Objects
4. Drag the cylinder to the beaker and empty the Virtual Fluid into the beaker.
Place the beaker on the balance and record the mass in Table 1. Drag the
beaker back to the cylinder to pour the fluid back in. Release when the
beaker snaps into place over the top of the cylinder.
84
Floating Objects
© Pearson Education, Inc. All rights reserved.
2. Use the Up and Down arrows on the control panel to toggle through the
options of fluids to use in the lab. Select the Virtual Fluid C. Click the Full
button underneath that display to select the amount of fluid to be added to
the cylinder. Click the Fill button to release the chosen amount of fluid into
the cylinder.
sx07CAGr8_VPhyLab_32.fm Page 85 Thursday, August 9, 2007 7:42 AM
Name ___________________________
Date ___________________
Class ____________
Table 1
Volume of Virtual Fluid (mL)
Mass of beaker only (g)
Mass of beaker and Virtual Fluid (g)
Determining Buoyant Force
5. Click on the cylinder to zoom in to record the volume again in Table 2.
6. Find the steel ball on the lab wall. Pick up the ball and drag it to the
spotlight on the balance. Record the mass in Table 2.
7. Drag the steel ball to the top of the cylinder and release it there. The ball
remains suspended above the fluid until you click the green Drop button,
which allows the ball to fall into the fluid. Click on the cylinder and record
the volume in Table 2.
Table 2
Volume of Virtual Fluid only (mL)
Volume of Virtual Fluid and steel (mL)
Mass of steel ball (g)
Analyze and Conclude
1. Calculating Use Table 1 to calculate the mass of the Virtual Fluid. How did
you determine it?
__________________________________________________________________
__________________________________________________________________
Use the formula below to calculate the density of the Virtual
Mass
Density --------------------Volume
or
dm
---V
__________________________________________________________________
Floating Objects
© Pearson Education, Inc. All rights reserved.
2. Calculating
Fluid.
Floating Objects
85
sx07CAGr8_VPhyLab_32.fm Page 86 Thursday, July 19, 2007 9:19 AM
Name ___________________________
Date ___________________
Class ____________
3. Problem Solving Archimedes’ principle states that the buoyant force
acting on a submerged object is equal to the weight of the fluid the object
displaces. You can determine the buoyant force on the steel sample by
following these steps:
First, determine the volume of Virtual Fluid displaced when the steel sample
was placed in the Virtual Fluid.
__________________________________________________________________
Second, determine the mass of the displaced Virtual Fluid. Use the formula
for density. Rearrange the formula to solve for mass.
__________________________________________________________________
Third, use the formula to calculate the mass of the Virtual Fluid.
__________________________________________________________________
4. Calculating The weight of an object is a measure of the force of gravity on
that object. You can calculate the weight of an object (in newtons) by
multiplying its mass (in kg) by 9.8 m/s2. Convert the mass of the Virtual
Fluid to kg. Then calculate the weight of the displaced Virtual Fluid in
newtons (N).
__________________________________________________________________
5. Drawing Conclusions What is the buoyant force acting on the steel ball?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
7. Relating Cause and Effect Explain why the steel ball sinks.
__________________________________________________________________
Floating Objects
__________________________________________________________________
86
Floating Objects
© Pearson Education, Inc. All rights reserved.
6. Drawing Conclusions What is the force of gravity (weight) acting on the
steel ball?
__________________________________________________________________
sx07CAGr8_VPhyLab_33.fm Page 87 Thursday, August 9, 2007 7:44 AM
Name ___________________________
Date ___________________
Class ____________
Lab 33: Density and Buoyancy
Purpose
Density and Buoyancy
To learn how to predict whether an object will float
Background
Why do some objects float and others sink? The answer lies in the density of
the objects and the liquid they are placed in. Density is the mass of a material in
one unit of volume. The mathematical formula for density is given below.
Mass
Density --------------------Volume
or
dm
---V
The formula shows that the mass is divided by the volume to obtain the
density. For this assignment, you will determine the density in g/mL of four
solids and four liquids. With this information, you can make predictions about
whether the solid materials will float in the liquids.
Skills Focus
Problem solving, predicting, calculating, drawing conclusions
Procedure
Density of a Solid
1. Start Virtual Physical Science. Select Density and Buoyancy from the list of
assignments. The lab will open in the Density laboratory.
© Pearson Education, Inc. All rights reserved.
2. Find the plastic sphere on the lab wall. Pick up the ball and drag it to the
spotlight on the balance. Record the mass in Table 1.
3. Use the Up and Down arrows on the control panel to toggle through the
options of fluids to use in the lab. Select the Virtual Fluid B. This is a unique
Virtual Fluid that is used only in this virtual laboratory. Click the Full button
underneath that display to select the amount of fluid to be added to the
cylinder. Click the Fill button to release the chosen amount of fluid into the
250 mL graduated cylinder on the laboratory bench. Click on the cylinder
to see a zoomed-in view of the level of the fluid. Record the volume of the
Virtual Fluid in Table 1.
4. Drag the plastic ball to the top of the cylinder and drop it in the cylinder of
Virtual Fluid. Click the green Drop button to let the ball fall into the fluid.
Look at the close-up view window to note the new volume with both the
Virtual Fluid and the plastic ball. Record the volume in the table.
Density and Buoyancy
87
sx07CAGr8_VPhyLab_33.fm Page 88 Thursday, August 9, 2007 7:44 AM
Name ___________________________
Date ___________________
Class ____________
Density and Buoyancy
5. Problem Solving How can you determine the volume of the plastic ball
from your measurements?
_________________________________________________________________
_________________________________________________________________
Record the volume of the plastic sample in Table 1. Click the handle at the
bottom of the cylinder to empty the contents of the cylinder.
6. Repeat Steps 2–4 for three samples: ice, aluminum, and pine wood. Record
your measurements in Table 1.
Table 1
Sample
Mass of
Sample
(g)
Volume of
Virtual
Fluid (mL)
Volume of
Virtual
Fluid and
Sample
(mL)
Volume
of
Sample
(mL)
Density
(g/mL)
Plastic
Ice
Aluminum
Pine Wood
Density of a Liquid
8. Click the Tare button on the balance. Taring the balance rezeros the balance
with whatever is on it. Drag the beaker on the counter to the balance and
record its mass in Table 2.
9. Pick up the cylinder filled with ethanol and pour it into the empty beaker.
Record the mass of the ethanol and beaker in Table 2.
10. Problem Solving How can you determine the mass of the ethanol in the
beaker?
_________________________________________________________________
88
Density and Buoyancy
© Pearson Education, Inc. All rights reserved.
7. Use the Up and Down arrows on the control panel to toggle through the
options of fluids to use in the lab. Select Ethanol. Click the Full button
underneath that display to select the amount of fluid to be added to the
cylinder. Click the Fill button to release the chosen amount of fluid into
the 250 mL graduated cylinder on the laboratory bench. Click on the
cylinder to see a zoomed-in view of the level of the fluid. Record the
volume in Table 2.
sx07CAGr8_VPhyLab_33.fm Page 89 Thursday, August 9, 2007 7:44 AM
Name ___________________________
Date ___________________
Class ____________
Record the mass of the ethanol in Table 2. Click the handle at the bottom of
the cylinder to empty the contents of the cylinder. Drag the beaker to the
container to the left of the Waste sign to empty the beaker.
Density and Buoyancy
11. Repeat steps 7–9 to obtain the densities of water, olive oil, and mercury.
Record your measurements in Table 2.
Table 2
Sample
Mass of
Empty
Beaker
(g)
Mass of
Beaker
and
Sample
(g)
Mass of
Sample
(g)
Volume of
Sample
(mL)
Density
(g/mL)
Ethanol
Water
Olive Oil
Mercury
Analyze and Conclude
1. Calculating Use the formula for density to calculate the density of each of
the solid samples. Record the answers in Table 1.
2. Calculating Use the same formula as above to calculate the density of each
of the liquid samples. Record the answers in Table 2.
3. Applying Concepts Does the weight of an object or its density determine
whether or not it will float in a fluid? Explain.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
4. Predicting Which of the solids will float in the olive oil? Explain.
__________________________________________________________________
__________________________________________________________________
Test your prediction by filling the cylinder with olive oil. Then move the
dispenser head over the next cylinder by clicking it and dragging it until it
clicks in place above the cylinder. Fill four cylinders with olive oil. Place
each of the objects in one of the cylinders and release them all to see whether
or not they will float.
5. Predicting Which of the solids will sink in mercury? Explain.
__________________________________________________________________
__________________________________________________________________
Empty all of the cylinders by clicking the release switches at the bottom of
the cylinders. Now test your prediction by filling all of the cylinders with
mercury. Place a different object in each one of the cylinders and release
them all to see whether or not they will sink.
Density and Buoyancy
89
sx07CAGr8_VPhyLab_33.fm Page 90 Thursday, July 19, 2007 9:23 AM
Name ___________________________
Date ___________________
Class ____________
Density and Buoyancy
6. Predicting What would you observe if olive oil and water were poured
together?
__________________________________________________________________
__________________________________________________________________
Test your prediction by half filling one of the cylinders with olive oil by
clicking the 1/2 button on the dispenser control before filling. That will allow
you to add half a cylinder of oil, then toggle through the fluids and select
water and dispense 1/2 of a fill of water to the same cylinder.
7. Drawing Conclusions If all four solids and all four liquids were mixed in
the same cylinder at the same time, what would you observe? List what you
would see from the top of the cylinder to the bottom. Explain how you
determined your placement.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
90
Density and Buoyancy
sx07CAGr8_VPhyLab_34.fm Page 91 Thursday, August 9, 2007 2:49 PM
Name ___________________________
Date ___________________
Class ____________
Lab 34: The Work of the Egyptians
Problem
To compare the amount of work needed to lift a 50m block of cement to the
amount of work and power needed to push the same block up a ramp
Background
The Work of the Egyptians
The Egyptians were able to build enormous pyramids because of their
understanding of the potential of the inclined plane. Because the Egyptians
were limited to manpower force to move each block of stone, they used ramps
as machines. Without an understanding of simple machines, manpower alone
could not have moved or lifted the blocks of stone—some with an average
weight of 2.5 tons each—that were used to build the pyramids. In this lab, you
will learn the relationship between work and power and the value of even
simple machines.
Skills Focus
Interpreting data, drawing conclusions, inferring
Procedure
1. Start Virtual Physical Science and select The Work of the Egyptians from the
list of assignments. The lab will open in the Mechanics laboratory. Note
that the laboratory will be set up with a sled at the bottom of the screen and
attached to the sled will be a rocket used to push the sled up in the air.
2. You will first push the sled straight up in the air and measure the force that
it takes to lift it up. Then push the sled up a ramp and measure the different
forces it takes to move up ramps of different angles.
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3. The mass of the sled is 50 kg. What is the weight of the sled? Remember
weight mass 3 acceleration due to gravity. Acceleration due to
gravity 9.8m/s2.
Weight of sled The Work of the Egyptians
91
sx07CAGr8_VPhyLab_34.fm Page 92 Friday, August 10, 2007 12:16 PM
Name ___________________________
Date ___________________
Class ____________
4. Determine the least amount of force necessary to lift the sled 50m. Change
the amount of force until you have the smallest force necessary to push the
sled to the top of the screen, which is 50m high. Click the Force button to
start the rocket for each trial. Watch the Y display at the bottom and stop
when the sled reaches 50m. If you have too much or too little force then use
the Reset button to reset and use the Parameters palette to increase or
decrease the force for the next trial. Record the approximate amount of
time it took the sled to reach the top. You may want to use the Time
Acceleration buttons to speed up time to make it to the top sooner. Click
the or signs by the Acceleration Display.
The Work of the Egyptians
Minimum Pushing Force
Time to reach top
5. Now find the least amount of force necessary to push the sled to the same
height using ramps of different angles. Notice that the table is made of
cement and the sled is made of cement. You will push the sled with
different amounts of force and watch it slide up the ramp.
Inferring. If the angle of the ramp is changed, what must change in order
to have the sled reach the same height as before (50m)?
_________________________________________________________________
92
The Work of the Egyptians
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6. Drag the Ramp icon on the tray at the top of the screen down into the
experiment area. Also pull down the friction icon (the ramp with a sled
icon already on it). Use the Ramp section in Parameters to change the angle
of the ramp and the length as indicated in the table below. (You already
completed the first row in the experiment.) To find the force necessary to
push the sled to the top, pick up the sled and drag it to the bottom of the
ramp, where Y 0. After each attempt, use the Reset button and make the
necessary changes before you begin your next trial. Complete Data Table 1
using the same technique as in steps 5 and 6.
sx07CAGr8_VPhyLab_34.fm Page 93 Thursday, August 9, 2007 2:49 PM
Name ___________________________
Date ___________________
Class ____________
Data Table 1
Ramp Angle
Ramp Length (m)
Force (N)
90°
50
491
60°
57.74
45°
70.71
30°
100
10°
287.94
7. Compute the work and power required to move the sled for each ramp.
Use Data Table 2 to compute work for each ramp. Remember the equations
for work force 3 distance.
Data Table 2
Force (N)
Ramp Length (m)
90°
50
60°
57.74
45°
70.71
30°
100
10°
287.94
The Work of the Egyptians
Ramp Angle
Work (J)
Analyze and Conclude
8. Recall Why did the length of the ramp need to change for the ramps of
different angles?
_________________________________________________________________
_________________________________________________________________
© Pearson Education, Inc. All rights reserved.
_________________________________________________________________
9. Analyze How did the pushing force change when the ramp angle
changed?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
10. Analyze How does changing the distance you have to push the sled affect
the work required?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
The Work of the Egyptians
93
sx07CAGr8_VPhyLab_34.fm Page 94 Thursday, August 9, 2007 2:49 PM
Name ___________________________
Date ___________________
Class ____________
11. If you had to help the Egyptians build a pyramid, explain which ramp you
would use and why you would want them to use it?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
The Work of the Egyptians
_________________________________________________________________
© Pearson Education, Inc. All rights reserved.
94
The Work of the Egyptians
sx07CAGr8_VPhyLab_35.fm Page 95 Thursday, August 9, 2007 2:50 PM
Name ___________________________
Date ___________________
Class ____________
Lab 35: Falling Elevator
Problem
To determine and understand the amount of force needed to bring an elevator
to a certain height and relate the work and power of the pulley system
Background
Skyscrapers are vital to the economies of large cities where there is limited area
for buildings. Stacking floors, as seen in high rises and skyscrapers, saves space
and allows for more office or living area. However, these tall buildings would
be impractical without elevators. Elevators make it possible to transport people
quickly and easily to all the floors. The cable elevator, which uses a pulley, is
the most popular today.
Skills Focus
Predicting, interpreting data, drawing conclusions
Procedure
1. Start Virtual Physical Science and select Falling Elevator from the list of
assignments. The lab will open in the Mechanics laboratory.
3. Click the Force button to turn on the rocket force and watch the sled
accelerate into the air. Now change the amount of force to find a range of
seconds that it would take to raise the elevator. First click the Reset button
to reset the lab, then open the Parameters Palette by clicking on the
Parameters button. Under the Force section you will see a text box where
you can enter different values for the force. Increase or decrease the
amount of force to push the elevator. After you change the force value, you
need to click somewhere else in the palette, or click Enter. Find the smallest
force that will lift the elevator. Record your trial forces in Data Table 1. Also
include the time it took for each trial. Use 0 in the time box to indicate if the
force was too little to lift the elevator.
Falling Elevator
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2. The laboratory will be set up with a sled located at the bottom of the screen.
The sled represents the elevator. A rocket is attached to the base of the sled.
You will use the rocket to accelerate the elevator to the designated height.
Calculate the height in meters by estimating that each floor of the
skyscraper is about 12 feet tall. Note that 1m is about 3 ft.
4. The mass of the sled represents a typical full capacity elevator, which is
about 3000kg.
Falling Elevator
95
sx07CAGr8_VPhyLab_35.fm Page 96 Thursday, August 9, 2007 2:50 PM
Name ___________________________
Date ___________________
Class ____________
Data Table 1
Mass (kg)
3000
3000
3000
3000
3000
Height
(number of
floors)
Height
(in meters)
Force
(N)
Time
(s)
20
20
20
20
20
Predict. What would the force required if you changed the mass to half
capacity, which would be as if the elevator was half full.
__________________________________________________________________
__________________________________________________________________
5. Change the mass of the sled, first click the Reset button and then open the
Parameters Palette and open the Object section. Change the mass to 1500kg
and then re-run the experiment for this new mass following the procedure
described in step 3. Record your new data in Data Table 2.
Mass (kg)
1500
1500
1500
1500
1500
Height
(number of
floors)
20
20
20
20
20
Force
(N)
Time
(s)
6. Determine the work and power required for both the full and half-full
elevators. Use the data from your trials that used sma ll forces. Remember
that work force 3 distance and power work/time. If any of your
calculations took long enough to output time in minutes, remember to
convert the time to seconds.
96
WORK
Full Elevator
Half Full
Force (N)
Distance (m)
Work (J)
POWER
Full Elevator
Half Full
Work (J)
Time (s)
Power (watts)
Falling Elevator
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Falling Elevator
Data Table 2
sx07CAGr8_VPhyLab_35.fm Page 97 Thursday, August 9, 2007 2:50 PM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
7. Which elevator required the most work to move? Why?
__________________________________________________________________
8. How can pulleys help reduce the amount of power required?
__________________________________________________________________
9. Think about the three types of pulleys. Why would you not use a single
fixed pulley to lift an elevator?
__________________________________________________________________
10. Using the table showing examples of horsepower related objects, explain
why there is a limit to the maximum load an elevator may carry.
1 horsepower is approximately equal to 750 watts.
Watts
Horsepower
Example
0–5000
0–6.7
Lawnmower
5001–10000
6.7–13.4
Electric motor bike
10001–15000
13.4–20.1
Riding lawn mower
15001–20000
20.1–26.8
Small air compressor
20001–30000
26.8–40.2
Small boat motor
30001–40000
40.2–53.6
Hot water boiler
40001–50000
53.6–67
Large air compressor
50001–100000
68–134
Small car engines
100001–500000
134–670
Muscle cars
+500000
+670
Airplanes
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Falling Elevator
Falling Elevator
97
sx07CAGr8_VPhyLab_36.fm Page 98 Friday, August 10, 2007 12:17 PM
Name ___________________________
Date ___________________
Class ____________
Lab 36: Thermal Energy
Problem
To calculate the amount of kinetic energy in a system and and observe how
energy changes when an outside force is applied
Background
What do you feel when you touch a hot frying pan? What do you feel when
you sit down on your car seat after your car has been sitting in the sun? What
do you feel when you pick up a plastic cup full of hot water? You feel the burn
of heat! These are examples of how you notice thermal energy. All matter
contains atoms, which move randomly throughout the substance. These atoms
have kinetic energy. Some objects are rigid solids, so the atoms aren’t as free to
move around, but they still have the potential to move and, in fact, are moving
slightly. The total potential and kinetic energy of an object make up its thermal
energy.
Skills Focus
Predicting, drawing conclusions, graphing, making models
Procedure
1. Start Virtual Physical Science and select Thermal Energy from the list of
assignments. The lab will open in the Mechanics laboratory.
Thermal Energy
3. Click on the Lab Book at the top of the screen to open it. Click the Red
button in the Recording section to start recording the data. Click the green
Start button to start the balls in motion. After a few seconds click the Pause
button to stop recording data. You will need to record the mass of each ball
and the velocity of each ball. You can find the mass of the balls in the
Parameters Palette under Objects. Record the data in the table below. Record
the velocities of each of the balls from the same period of time. The number
of the ball that is currently being tracked is located in the bottom right of
the screen. Use the arrows to scroll through each ball and record its total
velocity in Data Table 1. This value is located at the bottom of the screen in
the first row, second column (Vtot). Using the formula for Kinetic Energy =
1/2m·v2, where m is the mass and v is the velocity, calculate the kinetic
energy for each ball and record the total in the last row.
98
Thermal Energy
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2. The laboratory will be set up with 10 balls which represent molecules
inside of a substance. The system is enclosed by a box and thus the energy
is conserved. You will see that the atoms are in random motion. The kinetic
energy of the substance is calculated by adding up the kinetic energies of
all the particles that make it up.
sx07CAGr8_VPhyLab_36.fm Page 99 Friday, August 10, 2007 12:18 PM
Name ___________________________
Date ___________________
Class ____________
Data Table 1: Energy Level 1
Ball Number
Mass (kg)
1
2
3
4
5
6
7
8
9
10
10
20
10
15
5
1
100
200
7
1000
Kinetic
Energy (J)
Velocity (m/s)
Total Kinetic
Energy
Predicting. What will happen to the balls in the system when apply an
outside force?
4. Now place the plunger onto one of the balls in any direction you choose. Do
not reset the lab. Click the Force button to fire the plunger. This outside force
will change the velocity of the ball and change its kinetic energy. Wait a few
seconds to ensure the ball has transferred its energy to the system, then click
the Pause button. Again gather the total velocity for each ball. Use the new
table below to record the data for the new energy level of the system.
Ball Number
Mass (kg)
1
2
3
4
5
6
7
8
9
10
10
20
10
15
5
1
100
200
7
1000
Kinetic
Energy (J)
Velocity (m/s)
Thermal Energy
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Data Table 2: Energy Level 2
Total Kinetic
Energy
Thermal Energy
99
sx07CAGr8_VPhyLab_36.fm Page 100 Thursday, August 9, 2007 2:58 PM
Name ___________________________
Date ___________________
Class ____________
5. Repeat step 4 again, hitting one of the balls with the plunger and adding
more energy to the system. Record the data in the Data Table 3.
Data Table 3: Energy Level 3
Ball Number
Mass (kg)
1
2
3
4
5
6
7
8
9
10
10
20
10
15
5
1
100
200
7
1000
Kinetic
Energy (J)
Velocity (m/s)
Total Kinetic
Energy
2
Analyze and Conclude
7. Which energy level had the highest total kinetic energy?
_________________________________________________________________
8. If this were representing a molecule made up of many different atoms, at
which energy level would it be the most effective to use to heat up another
molecule? Why?
_________________________________________________________________
9. How could this model be used to represent energy transfer within a
molecule?
_________________________________________________________________
Thermal Energy
10. Make a bar graph of your data. On the x-axis you will graph the energy
level. On the y-axis you will graph the total kinetic energy.
100 Thermal Energy
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6. Go back and calculate the total kinetic energy for the system at the different
energy levels. Calculate the kinetic energy for each part of the system then
add them together. Use the column on the right to record the numbers for
each ball and then total those at the bottom in the total cell. Remember
Kinetic Energy 1--- mv2.
sx07CAGr8_VPhyLab_37.fm Page 101 Monday, August 13, 2007 2:19 PM
Name ___________________________
Date ___________________
Class ____________
Lab 37: Potential Energy to Kinetic Energy
Purpose
Potential Energy to
Kinetic Energy
To study the conversion of potential energy to kinetic energy by observing the
movement of an object down a ramp
Background
The conversion of energy between potential energy and kinetic energy is a
process that is observed throughout our daily lives. Any time an object falls off
of any height and speeds up as it falls to the ground, we are observing a
transformation of energy.
Skills Focus
Predicting, interpreting data, drawing conclusions
Procedure
1. Start Virtual Physical Science and select Potential Energy to Kinetic Energy
from the list of assignments. The lab will open in the Mechanics laboratory.
2. The laboratory will be setup with a sled on a ramp and with gravity pulling
vertically down. The surface is frictionless. You will release the sled from
different heights and watch it slide down the ramp. You will measure the
speed of the sled at the base of the ramp and use that to calculate the
kinetic energy.
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3. Predicting Where on the ramp do you think the sled has the most total
energy? At the top, somewhere in the middle of the slope, or at the bottom
where the sled is moving fastest?
__________________________________________________________________
4. You will be measuring the height of the sled and the speed of the sled when
it hits the bottom. In Data Table 1 record the Y height of the sled, found in
the left hand side of the data table at the bottom of the screen next to Y.
Click the red Start button in the Experiment Control panel to release the
sled. It will slide to the bottom of the ramp and explode when it hits the
bottom. Record the total velocity found in the display next to V tot.
5. Now repeat the experiment four more times, starting the sled in a different
place every time. Click the blue Reset button to return the sled to the top of
the ramp. Click on the sled and move it down the ramp to a different
height. Remember to record the Y height in the table and then start it
sliding by clicking Start. Record the total velocity in the Data Table 1
after each run.
Potential Energy to Kinetic Energy
101
sx07CAGr8_VPhyLab_37.fm Page 102 Monday, August 13, 2007 2:20 PM
Name ___________________________
Date ___________________
Class ____________
Data Table 1
Potential Energy to
Kinetic Energy
Height of the
Sled (Y) (m)
Speed at the
bottom (Vtot)
(m/s)
Initial
Potential
Energy (J)
Final Kinetic
Energy (J)
6. To calculate the potential energy of the sled, you need to know its mass.
Click on Parameters and select Objects to find the mass of the object.
Gravitational potential energy is calculated with the following formula:
PE = mgh, where m is the mass of the object in kilograms, g is the
gravitational constant = 9.8 m/s2, and h is the height of the object in meters.
Calculate and record in the table the initial potential energy of the object for
the five cases that you tried.
7. Now compute the kinetic energy of the object at the end of the ramp.
Kinetic energy is calculated by knowing the mass of the object and the
velocity. KE = 1--- mv2, where m is the mass of the object in kilograms and v is
2
the velocity, or speed, of the object. Calculate and record in the table the
final kinetic energy of the object in the five cases you tried.
9. Now measure the energy of the sled throughout the course of a run. Reset
the experiment and in Data Table 2 record the initial height of the sled and
its speed as explained in step 5. Start the sled moving down the ramp and
somewhere in the middle of the ramp click Pause and record the Y height
and speed. Start the sled sliding again and let it slide to the bottom of the
ramp. Record the Y height and speed in the table again.
10. Calculate the potential and kinetic energies at each step as explained in
steps 6 and 7.
102 Potential Energy to Kinetic Energy
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8. Interpreting Data What do you notice about the quantities you just
calculated for initial potential energy and final kinetic energy?
__________________________________________________________________
sx07CAGr8_VPhyLab_37.fm Page 103 Friday, August 10, 2007 8:09 AM
Name ___________________________
Date ___________________
Class ____________
Data Table 2
Height of the
Sled (Y) (m)
Speed (Vr)
(m/s)
Potential
Energy (J)
Kinetic
Energy (J)
Potential Energy to
Kinetic Energy
Initial:
Middle:
Bottom:
11. The ramp has been set at an angle of 45 degrees for all of the previous
experiments. Now you will change the angle of the ramp and measure the
energy of the sled when released on different slope ramps. Reset the
experiment.
12. You can copy your first row of data from Data Table 1 into the first row of
Data Table 3. Now in the Parameters Ramp section change the angle of the
ramp to the next angle listed in the table and move the sled down the ramp
to the same Y height that it was at in the first run. Click Start to run the
experiment and record the speed at the bottom as described in step 4.
Calculate the kinetic energy for that run. Reset the experiment and change
the ramp again to the next listed angle. Repeat the experiment as described
above. If necessary increase the length of the ramp to be able to place the
sled at the same initial height.
Data Table 3
Ramp Angle
Height of the
Sled (Y) (m)
Speed at the
bottom (Vr)
(m/s)
Kinetic
Energy (J)
45°
60°
15°
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Your choice: ___
Analyze and Conclude
1. Analyze How did the kinetic energy change by changing the angle?
__________________________________________________________________
2. Analyze How did the kinetic energy change throughout the course of
sliding down the ramp? How did the total energy (kinetic and potential)
change throughout a run?
__________________________________________________________________
3. Where is energy generally lost to as objects move in real life?
__________________________________________________________________
Potential Energy to Kinetic Energy
103
sx07CAGr8_VPhyLab_38.fm Page 104 Monday, August 13, 2007 2:22 PM
Name ___________________________
Date ___________________
Class ____________
Lab 38: Temperature and Volume of a Gas
Purpose
To learn about the relationship between the temperature and the volume of a gas
Background
Charles’s Law was discovered by Joseph Louis Gay-Lussac in 1802 based on
unpublished work done by the French scientist Jacques Charles in about 1787.
Charles’s law describes the relationship between the temperature of a gas and
its volume. You will make observations similar to those made by Charles. You
will change the temperature of a gas while keeping all other variables constant
and observe what happens to the volume of the gas.
Temperature and Volume
of a Gas
Skills Focus
Graphing, predicting, interpreting data, controlling variables, drawing
conclusions
Procedure
1. Start Virtual Physical Science and select Temperature and Volume of a Gas from
the list of assignments. The lab will open in the Gases laboratory. Note that
the balloon in the chamber is filled with a gas at a temperature of 100°C. The
pressure of the gas is 101.3 kPa. Its volume is 1531 cm3.
3. Record in the table the beginning temperature and volume of the gas. Click
on the 1 in the temperature window. The digit should turn green. Type 2, so
that the temperature is now 200°C. Record the new temperature and volume
in the table. Repeat this step again but type a 3 in the temperature window.
Again, record your data. Continue to increase the temperature by 100°C
each time and record your data until you reach 700°C.
Temperature (°C)
104 Temperature and Volume of a Gas
Volume (cm3)
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2. Predicting You are going to increase the temperature of the gas in the
balloon. What effect will the change in temperature have on the volume of
the balloon? Record your prediction.
__________________________________________________________________
sx07CAGr8_VPhyLab_38.fm Page 105 Friday, August 10, 2007 8:05 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
Temperature and Volume
of a Gas
© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.
1. Graphing Make a line graph of the data obtained in Step 3. Show
temperature in °C on the horizontal axis and volume in cm3 on the vertical
axis.
2. Drawing Conclusions Did the results you obtained support your
prediction? Explain.
__________________________________________________________________
3. Interpreting Graphs Is the relationship between temperature and volume
linear or nonlinear?
__________________________________________________________________
4. Predicting If the temperature were decreased, how would the volume of
the gas change?
__________________________________________________________________
To check your prediction, decrease the temperature on the balloon by
pulling down on the lever on the temperature controller until the tens digit
turns blue and holding the lever. Observe the balloon’s volume as the
temperature decreases.
Temperature and Volume of a Gas
105
sx07CAGr8_VPhyLab_39.fm Page 106 Monday, August 13, 2007 2:39 PM
Name ___________________________
Date ___________________
Class ____________
Lab 39: Specific Heat
Purpose
To measure the specific heat of several different metals to better understand the
implications of heat capacity on product design.
Background
On a hot summer day, it is always refreshing to jump into a pool because the
water is cooler than the air around you and the ground that is roasting your
feet. This may seem strange since the water and ground are being heated by the
same source—the sun. This evidence suggests it takes more heat to raise the
temperature of some substances than others, which is true. The amount of heat
required to raise the temperature of 1 g of a substance by 1 degree Celsius is
called the specific heat capacity, or specific heat, of that substance. In this
experiment, you compare the specific heats of various metals to see how the
specific heat of the metal affects how fast it changes temperature and you will
see why soda cans are made out of the material they are made out of.
Skills Focus
Measuring, calculating, applying concepts, making judgments
Procedure
2. You will be measuring the heat capacity of Al, Au, and Stainless Steel.
Make sure to keep track of which sample you are testing by keeping
accurate notes. Click on the Lab Book to open it. Record the mass of Al on
the balance. If it is too small to read click on the Balance area to zoom in,
record the mass of Al in the Data Table, and return to the laboratory.
3. Pick up the Al sample from the balance pan and place the sample in the
oven. Click the oven door to close. The oven is set to heat to 200°C.
4. The calorimeter has been filled with 100 mL water. The density of water at
25°C is 0.998 g/mL. Use the density of the water to determine the mass
from the volume and record the volume and mass in the Data Table.
Make certain the stirrer is On (you should be able to see the shaft rotating).
Click the thermometer window to bring it to the front and click Save to
begin recording data. Allow 20-30 seconds to obtain a baseline temperature
of the water.
5. Click on the Oven to open it. Drag the hot aluminum sample from the oven
until it snaps into place above the calorimeter and drop it in. Click the
thermometer and graph windows to bring them to the front again and
106 Specific Heat
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Specific Heat
1. Start Virtual Physical Science and select Specific Heat from the list of
assignments. The lab will open in the Calorimetry laboratory.
sx07CAGr8_VPhyLab_39.fm Page 107 Monday, August 13, 2007 2:39 PM
Name ___________________________
Date ___________________
Class ____________
observe the change in temperature in the graph window until it reaches a
constant value and then wait an additional 20–30 seconds. Click Stop in the
thermometer window. (You can click on the clock on the wall labeled
Accelerate to accelerate the time in the laboratory.) A blue data link will
appear in the lab book. Click the blue data link and in the Data Table record
the temperature before adding the Al and the highest temperature after
adding the Al. (Remember that the water will begin to cool down after
reaching the equilibrium temperature.)
6. Repeat the experiment with an Au sample. Click the red disposal bucket to
clear the lab. Click on the Stockroom to enter. Double-click the Dewar
calorimeter to move it to the Stockroom counter. Click the metal sample
cabinet. Open the top drawer (the samples are alphabetically arranged) by
clicking on it, select the Au by double-clicking and zoom out. Double-click
on the Petri dish with the selected sample to move it to the Stockroom
counter. Return to the laboratory.
7. Move the Petri dish with the sample to the spotlight next to the balance.
Move the metal sample to the balance pan and record the mass in the Data
Table. Return to the laboratory.
Specific Heat
8. Double-click the calorimeter to move it into position in the laboratory.
Click the oven to open the door. Move the metal sample from the balance
pan to the oven and click to close the oven door. Click above the tens place
several times on the front of the oven to change the temperature to 200°C.
Fill the 100 mL graduated cylinder with water by holding it under the tap
until it returns to the counter and then pour it into the calorimeter. Turn on
the stirrer. Turn on the thermometer. Click on the Graph and Save buttons.
Move your metal sample from the oven to the calorimeter. Follow the
procedures used with Al to obtain the equilibrium temperature. Record all
of your observations in the Data Table. Repeat for steel.
© Pearson Education, Inc. All rights reserved.
Data Table
Al
Au
Stainless
Steel
mass of metal (g)
volume of water (mL)
mass of water (g)
initial temperature of water (°C)
initial temperature of metal (°C)
max temp of water + metal (°C)
Specific Heat (J/g°C)
Specific Heat
107
sx07CAGr8_VPhyLab_39.fm Page 108 Monday, August 13, 2007 2:39 PM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
9. Determine the changes in temperature of the water (ΔTwater).
10. Calculate the heat (q) gained by the water using the following equation:
qwater = mwater • Twater, • Cwater given = 4.184 J/(g°C)
11. Determine the changes in temperature of the Al (ΔTAl).
12. Remembering that the heat gained by the water is equal to the heat
lost by the metal, calculate the specific heat of the metal.
qwater = qmetal = mAl• TAl• CAl which when solved for the heat
q
( m metal ) ( T metal )
metal
. Record your result in the Table.
capacity is: CAl = ----------------------------------------------
13. Repeat the calculation of specific heat capacity for Au and record your
result in the Data Table.
Specific Heat
15. Applying Concepts Heat capacity is a numerical way to express how
much heat it takes to heat something up 1 degree. So an object with low
heat capacity requires very little heat to heat it up, while an object with
high heat capacity takes a lot of heat to change its temperature. If you have
a can made of gold and one made of aluminum, describe what will happen
to the temperature of the can when you pull it out of the refrigerator.
Include in your discussion connections to the specific heat of the metals.
16. Making Judgements Many cooking pans are made out of steel and there
are also some made of aluminum. Discuss which type of pan you think
would be better.
__________________________________________________________________
__________________________________________________________________
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108 Specific Heat
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14. Repeat the calculation of specific heat capacity for Steel and record your
result in the Data Table.
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Date ___________________
Class ____________
Lab 40: Blackbody Radiation
Purpose
To study the radiation emitted by a glowing metal filament
Background
In the early 1900s several experimental results appeared to be in conflict with
classical physics. One of these experiments was the study of blackbody
radiation. A blackbody is a solid (such as a piece of iron) that does not emit
light at low temperatures, but, when heated, the blackbody begins to emit first
red and then orange light and at higher temperatures eventually becomes
white hot. The intensity of the emitted light is also a function of temperature.
In this lab, you will make observations of the radiation emitted by a tungsten
filament, the same type of metal that is used in incandescent light bulbs.
Skills Focus
Measuring, graphing, interpreting graphs, drawing conclusions, developing
hypotheses
Procedure
1. Start Virtual Physical Science and select Blackbody Radiation from the list of
assignments. The lab will open in the Quantum laboratory. A metal sample
holder with tungsten metal will be on the lab bench with an electric heater
set at a temperature of 3000 K. A spectrometer is on the right and is switched
on (the spectrometer window is open).
Blackbody Radiation
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2. The spectrometer detects the intensity of the emitted light as a function
of the wavelength (or frequency). In the grid on the next page draw the
spectrum detected by the spectrometer with wavelength (in nm) on the
x-axis and intensity on the y-axis.
Blackbody Radiation
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Date ___________________
Class ____________
If you drag your cursor over a peak, it will identify the wavelength (in nm)
in the x-coordinate field in the bottom right corner of the detector window.
Record the wavelength of the peak in the data table. (Round to whole
numbers.)
Data Table
Temperature (K)
3000
3100
3200
3300
Blackbody Radiation
3400
3500
3600
110 Blackbody Radiation
Wavelength (nm)
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3. Change the temperature on the heater to 3100 K by clicking on the button
above the hundreds place on the heater LCD controller. Record the shape of
the curve on the same graph (label each line with a temperature) and the
wavelength of the peak intensity in the data table. Continue with
temperatures of 3200 K, 3300 K, 3400 K, 3500 K, and 3600 K. If you raise the
temperature to 3700 K you will have to start over. Click on the Reset Lab
button just under the Danger sign, enter the Stockroom, click on the
clipboard and select Preset Experiment #3: Blackbody Radiation.
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Name ___________________________
Date ___________________
Class ____________
4. What observations can you make about the shape of the curve as
temperature changes?
__________________________________________________________________
__________________________________________________________________
5. The visible portion of the electromagnetic spectrum occurs between
400 nm and 700 nm. Mark the visible spectrum on your graph.
Interpreting Graphs Does the peak intensity ever occur in the visible
region? Does this mean that there is no visible light radiated over this
temperature range? Explain.
__________________________________________________________________
__________________________________________________________________
6. Drawing Conclusions You can see on the graph that many different
wavelengths of electromagnetic radiation are emitted as the tungsten is
heated. The peak in the curve, or area where the most radiation is emitted, is
at a longer wavelength than visible light. This range is called the infrared
region, which humans can't see with their eyes, but can feel as heat. The
metal in heat lamps also radiates infrared rays as it heats up, but you can see
the coils glowing because it also emits some light in the visible range, just
like this tungsten. As the temperature increases, what do you notice about
the intensity or the peak height? As a light bulb heats up, should it radiate
more light?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
7. Developing Hypotheses Light bulbs are actually built to limit the amount
of electrical power they can draw, to limit how fast they can burn out. Light
bulbs do burn out though, why do you think that is?
__________________________________________________________________
__________________________________________________________________
Blackbody Radiation
© Pearson Education, Inc. All rights reserved.
__________________________________________________________________
Blackbody Radiation
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Lab 41: Wave Properties of Light
Wave Properties
of Light
Purpose
To study the single slit and double slit diffraction experiments
Background
It has long been known that if you shine light through narrow slits that are
spaced at small intervals, the light will form a diffraction pattern. A
diffraction pattern is a series of light and dark patterns caused by wave
interference. The wave interference can be either constructive (light
patterns) or destructive (dark patterns). In this experiment, you will shine a
laser through a device with two slits where the spacing can be adjusted and
investigate the patterns that will be made at a distance from the slits.
Skills Focus
Predicting, drawing conclusions, observing
Procedure
1. Start Virtual Physical Science and select Wave Properties of Light from the
list of assignments. The lab will open in the Quantum laboratory.
2. What source is used in this experiment and for what reason?
What is the wavelength of the Laser?
In the space below, draw a picture of the pattern displayed on the video
screen.
112 Wave Properties of Light
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What is the spacing of the two slits on the two slit device?
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3. Change the Intensity of the Laser from 1 nW to 1W.
Does the intensity of the light affect the diffraction pattern?
Wave Properties
of Light
Change the Slit Spacing to 1 m. Observe the pattern displayed on the
video screen as you change the slit spacing from 1 m to 7 m by
one-micrometer increments. What can you state about the relationship
between slit spacing and diffraction pattern?
4. Predicting What do you think would happen if you made the spacing
between the slits smaller than the size of the wavelength? What will
happen if the spacing between the slits is greater than the size of the
wavelength?
5. Drawing Conclusions When the slits are very close together, it
appears to be just one slit, and we see a basic diffraction pattern;
however, once we spread out the slits, we can start to see interference
when waves passing through the two different slits interfere with each
other. Confirm your prediction above and write your observation of the
difference in the diffraction patterns between spacings less than and
greater than the wavelength size.
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6. Increase the Wavelength of the Laser to 700 nm. What affect does an
increase in the wavelength have on the diffraction pattern?
Wave Properties of Light
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Wave Properties
of Light
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Date ___________________
Class _____________
7. Observing Decrease the Intensity on the Laser to 1000 photons/second.
Click on the Persist button on the video camera to look at individual
photons coming through the slits. Observe for one minute. What
observation can you make about this pattern as compared to the pattern
from the continuous beam of photons?
Decrease the Intensity to 100 photons/second. Observe for another
minute after clicking Persist. At these lower intensities (1,000 and 100
photons/second), there is never a time when two photons go through
both slits at the same time. How can a single photon diffract?
8. Drawing Conclusions From this experiment, what conclusions can
you make about the nature of light?
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114 Wave Properties of Light
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Lab 42: Particle Properties of Light
Purpose
To study the photoelectric effect and understand the connection between
the wavelength and energy of photons.
Background
Particle Properties
of Light
Though Albert Einstein is most famous for E mc2 and his work in
describing relativity in mechanics, his Nobel Prize was for understanding a
very simple experiment. It was long understood that if you directed light of
a certain wavelength at a piece of metal, it would emit electrons. In classical
theory, the energy of the light was thought to be based on its intensity and
not its frequency. However, the results of the photoelectric effect
contradicted classical theory. These inconsistencies led Einstein to suggest
that we need to think of light as being comprised of particles (photons) and
not just as waves.
The energy of a photon is directly proportional to the frequency of light,
and inversely proportional to the wavelength of light. This means that light
of longer wavelengths has less energy than light of shorter wavelengths.
You will be using light of different wavelengths and you will compare and
rank the amounts of energy.
Skills Focus
Observing, comparing and contrasting, drawing conclusions
Procedure
1. Start Virtual Physical Science and select Particle Properties of Light from the
list of assignments. The experiment opens in the Quantum laboratory.
© Pearson Education, Inc. All rights reserved.
2. What source is used in this experiment and what does it do?
At what intensity is the laser set?
At what wavelength is the laser set?
Record the wavelength (in nm) in the data table.
Which metal foil is used in this experiment?
Particle Properties of Light
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What detector is used in this experiment and what does it measure?
Turn on the detector by clicking on the red/green light switch. What
does the signal on the phosphor screen indicate about the laser light
shining on the sodium foil?
3. Decrease the Intensity to 1 photon/second. How does the signal change?
Particle Properties
of Light
Increase the Intensity to 1 kW. How does the signal change?
4. Change the Intensity back to 1 nW and increase the Wavelength to 600
nm. What do you observe? Record the wavelength in the data table.
Determine the maximum wavelength at which emission of electrons
occurs in the metal.
Wavelength (nm)
Energy
Light color
5. Rank the amount of energy of each wavelength of light. Determine the
color of the light by clicking on the Spectrum Chart (just behind the laser);
the markers indicate what color is represented by the wavelength
selected. Record the colors in the table.
116 Particle Properties of Light
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Data Table
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6. Comparing and Contrasting What is the difference between intensity
and wavelength?
Which matters in the formation of photoelectrons: intensity or
wavelength?
7. Drawing Conclusions Summarize what you have observed about
which wavelengths and energies of light can cause electrons to be
emitted from a metal plate. Include a description of the effect of varying
the intensity of light on the amount of electrons emitted.
© Pearson Education, Inc. All rights reserved.
Particle Properties
of Light
Particle Properties of Light
117
sx07CAGr8_VPhyLab_43.fm Page 118 Tuesday, August 14, 2007 7:21 AM
Name ___________________________
Date ___________________
Class ____________
Lab 43: Atomic Emission Spectra
Purpose
To study the colors of light emitted as a current is passed through various gases
used in common lighting devices
Background
In the 1800s, scientists found that when a sample of gas was excited by an
electric field, light with only certain discrete wavelengths was emitted. This
property allowed for the development of spectroscopic techniques that can be
used in the identification and analysis of elements and compounds. Niels Bohr,
a Danish physicist, first proposed that energy levels of electrons are quantized
and that excited electrons can only fall to discrete energy levels, which explains
why when electricity was run through a gas, it did not emit all colors in the
visible spectrum. This assignment illustrates the measurements that helped
Bohr develop his original quantum model, as well as some practical uses for
this science by measuring the emission spectra for various gases that are
common in lights.
Skills Focus
Observing, comparing and contrasting
1. Start Virtual Physical Science and select Atomic Emission Spectra from the list
of assignments. The lab will open in the Quantum laboratory. A sample of
gaseous sodium is on the lab bench in a sample tube and an alternating
electric field of 300 V has been applied to cause the sodium gas to emit light.
A spectrometer is on the right side of the lab bench and has been turned on.
You can separate the light in an emission spectrum by using an optical prism
or a diffraction grating. A spectrometer is an instrument designed to
separate the emitted light into its component wavelengths. The detector
window shows the output from the spectrometer.
2. Click on the Visible/Full switch in the detector window to change the output
from the spectrometer to the visible spectrum. One spectral line is much
more intense than all the others.
Observing What is the color and wavelength (in nm) of this line? (To
determine the wavelength, move the cursor over the line and read the
wavelength in the x field at the bottom of the detector window. Look at the
color at the top of the Spectrometer screen that corresponds to the peak
wavelength.) Record your observations in the Data Table.
Sodium vapor lights are becomming popular because of their energy
efficiency and bright light. Astronomers are excited about cities changing
from normal incandescent streetlights to sodium vapor streetlights because
astronomers can easily filter out the peak at 589 nm and minimize light
pollution. Incandescent lights emit light at all wavelengths of the visible
spectrum and make filtering impractical.
118 Atomic Emission Spectra
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Atomic Emission Spectra
Procedure
sx07CAGr8_VPhyLab_43.fm Page 119 Tuesday, August 14, 2007 7:21 AM
Name ___________________________
Date ___________________
Class ____________
3. You will test different types of gases to observe the colors and characteristics
of different lights. To exchange gas samples, double-click or click and drag
the Electric Field and place it on the stockroom counter, and double-click or
click and drag the Gas (Na) sample tube and place it on the stockroom
counter as well. You may have to click on the main laboratory window in
order to move the items.
4. Enter the stockroom by clicking in the Stockroom. Click on the Gases samples
on the top shelf. Click on the cylinder labeled Hg to replace the Na in the
sample tube with mercury vapor. If you point to the gas sample tube with
the cursor it should read Hg.
5. Return to the laboratory and drag the gas sample tube off the stockroom
counter and place it in the middle of the table as indicated by the spotlight.
Drag the Electric Field and place it on the gas sample tube. Carefully click the
button just above the left zero on the Electric Field controller and change the
voltage to 300 V. Turn on the Spectrometer by clicking on the red/green button.
Atomic Emission Spectra
6. Comparing and Contrasting How does the spectrum for mercury look
different from sodium? Record the color in the Data Table.
Click on the Visible/Full switch in the detector window to change the output
from the spectrometer to the full spectrum. You should see many more peaks
in the ultraviolet range-to the left of the blue peak. The emitted light is not
very bright for just the mercury vapor, but when scientists examined the full
spectrum for mercury they saw what you just observed. There is an enormous
emission in the ultraviolet region (UV). This light is sometimes called black
light. You may have seen it with glow-in-the-dark displays.
Scientists coat the inside of the glass tube of fluorescent light tubes with a
compound that will absorb UV and emit the energy as visible light with all
the colors of the visible spectrum. All colors together create white light,
which is why fluorescent light tubes emit very white light.
7. Repeat steps 3–6 for the rest of the gases listed below in the table.
Data Table
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Gas
Color of Light
(highest peaks in visible Range)
Sodium (Na)
Mercury (Hg)
Neon (Ne)
Hydrogen (H2)
Helium (He)
8. Observing Now you understand how neon lights can be different colors,
depending on the type of gas inside the tubes. Designers can mix gases to
create other colors or can color the tubes that the gas is in to add to the effect.
What colors of neon lights have you seen?
Atomic Emission Spectra
119
sx07CAGr8_VPhyLab_44.fm Page 120 Tuesday, August 21, 2007 12:42 PM
Name ___________________________
Date ___________________
Class ____________
Lab 44: Plane Mirror Images
Purpose
To study the images observed in plane mirrors and to examine what a virtual
image means
Background
Mirrors are everywhere. They are used to see images of ourselves, cars behind
us, even to the stars. Plane mirrors are the most common type of mirrors. They
have flat surfaces, and the image you see in them is exactly the same size as the
original object.
Skills Focus
Predicting, observing, designing experiments
Procedure
1. Start Virtual Physical Science and select Plane Mirror Images from the list of
assignments. The lab will open in the Optics laboratory.
2. The laboratory will be set up with a candle on an optics table with a plane
mirror in front of it. An eye will be set up at exactly the same distance from
the mirror to be used as a detector, to look at the candle reflection in the
mirror. You will observe the image of the candle from various distances and
also observe the image of a beach ball to determine how images are changed
in a mirror.
4. Mouse over the eye and a rotation control panel will appear. Rotate the eye
to 90 degrees, so it is directly facing the candle. Sketch the candle as seen by
directly looking at it on the optics table. Then rotate the eye to face towards
the image from the mirror, at about 0 degrees. You can see the image of the
candle in the Virtual Eye detector screen. Sketch the image of the candle that
you see in the mirror.
Plane Mirror Images
Candle as seen from above
Candle as seen in mirror
5. Click on the eye and drag it farther back on the table. How did the image
change when you pulled back the viewing eye?_________________________
120 Plane Mirror Images
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3. Predicting What do you think will happen to the image of the candle as
the eyeball is pulled farther and farther back?__________________________
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Name ___________________________
Date ___________________
Class ____________
6. The virtual eye does not have a lens in it, like human eyes do, which means
that light isn’t focused down to a point, and you will not see variations in
image size due to distance. The virtual eye is just a detector screen that light
rays are reflected on to. The detector screen and the mirror are both bigger
than the object, like a full body sized mirror. Since there is nothing to bend
the light rays, they continue to travel in straight lines, no matter how far
they are from the mirror.
7. Study how the image orientation is produced in a plane mirror. Click on the
candle and drag it to the tray next to the beach ball. Click on the beach ball
and bring it back to the optics table to where the candle in the same row of
peg holes as the eye was. Use a colored pencil to draw in the colors of the
ball in the correct order. Now drag the ball back to the position that the
candle was in, so the eye can see the image of the ball from the mirror. The
white images lines are displayed to help you find the sight line. Sketch the
image of the ball as seen in the mirror below, making sure to correctly order
the colors as you see them again.
Beach ball as seen in 1st mirror
Beach ball as seen in 2nd mirror
8. Pick up another mirror from the tray at the top of the table, and place it in a
position so the light from the mirror can bounce on the second mirror too.
You will probably need to rotate the mirror to face the direction of the
bouncing light. The arrow head on the mirror indicates the reflective side.
Now move the detector to be in line with the light bouncing off the second
mirror. Rotate the eye as needed. You may need to adjust the orientation of
your mirrors and detector so the sight line from the actual object is blocked.
If you don’t, you will have multiple images displayed in the detector
simultaneously and it might be hard to see which is the reflected image and
which is the actual object. ___________________________________________
9. Analyzing What observations did you make about the orientation of an
image in a mirror? Where does the image appear to be?
Plane Mirror Images
© Pearson Education, Inc. All rights reserved.
Beach ball as seen directly
10. Plane mirrors reflect what is called virtual images, images that seem to be
inside the mirror or on the other side of the mirror, when actually no light
can penetrate through the mirror. If you put a piece of paper behind the
mirror, no image would show because the light isn’t really making it to
that point. Devise and execute an experiment you could do to test this
hypothesis.
Plane Mirror Images
121
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Name ___________________________
Date ___________________
Class ____________
Lab 45: Concave Mirror Images
Concave Mirror Images
Purpose
To study the images created in concave mirrors and to examine the relationship
between the orientation of images and the location of the object in front of the
mirror
Background
Not all mirrors are flat, like plane mirrors. Concave mirrors reflect light on the
inside of the curved surface. Because of this inside curve, the image that’s seen
changes depending on the distance between the object and the mirror.
Flashlights and car headlights use concave mirrors because they require light to
be focused into a narrow beam.
Skills Focus
Predicting, inferring, drawing conclusions
Procedure
1. Start Virtual Physical Science and select Concave Mirror Images from the list
of assignments. The lab will open in the Optics laboratory.
3. Predicting What do you think will happen to the image of the gnome as
the object is pulled farther and farther back from the mirror?
4. Click on the gnome and drag it to the left of the detector, in the same row of
peg holes. Mouse over the eye and a rotation control panel will appear.
Rotate the eye to face the gnome and sketch it in the box below. Return the
gnome to its original position and rotate the eye back to 5 degrees. Sketch
the reflected image that you see in the mirror.
Gnome as seen from above
122 Concave Mirror Images
Gnome as seen in mirror
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2. The laboratory will be set up with a garden gnome on an optics table with a
concave mirror in front of it. A detector, or virtual eye, is also placed on the
table so it can look at the reflection in the mirror. You will observe the
image of the gnome from various distances to determine how images are
changed in a concave mirror.
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Name ___________________________
Date ___________________
Class ____________
Concave Mirror Images
5. When light hits a concave mirror, it is all directed forward into a point in
front of the mirror called a focal point. When the object you are looking at
is farther away from the mirror than the focal point, the light from the
object passes through the focal point and away at an angle, forming an
upside down real image. When the object is between the mirror and the
focal point, the image is called a virtual image, is right side up and seems to
come from the other side of the mirror. Since light does not actually pass
through the mirror, the image is referred to as a virtual image
6. Inferring What can you infer about the location of the object with respect
to the focal point based on what you observed in the mirror? Are you
observing a real or virtual image? Note the Height Factor displayed in the
bottom of the detector screen. This is the magnifying factor of the image
from the original size of the object. Record the value.
_________________________________________________________________
7. Click on the object and drag it a little farther back on the table. Observe the
image of the gnome. You may need to rotate the mirror so the image line
hits the detector. How did the image change when you pulled back the
object? How have the height factor and orientation of the image changed?
_________________________________________________________________
8. Keep dragging the object farther and farther back and observe the size of
the image as you pull back. What happens to the orientation of the image
and the size of the image as you pull the object farther and farther back
from the mirror?
_________________________________________________________________
© Pearson Education, Inc. All rights reserved.
_________________________________________________________________
9. There is a certain point in front of the mirror through which all light is
reflected. This is called the focal point. Light that reflects through that point
bounces off the mirror in parallel rays and never intersects again. Observe
what happens when you put an object in the focal point. Move the object
towards the mirror from its current location, checking the image frequently.
If you are farther away than the focal point, the image will be upside down,
and then when you are past the focal point the image will be right side up,
Keep moving it around that changing area to see if you can find the focal
point. It may be easier to find the focal point if you move the gnome to the
same line of pegs that the mirror is on. What happens to the image in that
point?
_________________________________________________________________
Concave Mirror Images
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sx07CAGr8_VPhyLab_46.fm Page 124 Tuesday, August 14, 2007 8:24 AM
Name ___________________________
Date ___________________
Class ____________
Lab 46: Convex Mirror Images
Purpose
To study the images created in convex mirrors and to measure the relationship
between the apparent size of the images and the real distance to the object in
front of the mirror
Background
Convex Mirror Images
When you look at yourself in the back of a spoon or any other curved mirror
where the mirror curves towards you, you are looking in a convex mirror. This
type of mirrors reflects light on the outside of the curved surface. Convex
mirrors are used to minimize the size of an object and are often seen in rear
view mirrors on cars where it says, “Objects in mirror are closer than they
appear.”
Skills Focus
Predicting, making judgments, controlling variables, measuring
Procedure
1. Start Virtual Physical Science and select Convex Mirror Images from the list of
assignments. The lab will open in the Optics laboratory.
3. Predicting What do you think will happen to the image of the candle that
you see in the mirror as the object moves closer and closer to the mirror?
4. Mouse over the eye and a rotation panel will appear. Rotate the eye to face
the candle at about 235 degrees. Sketch the object in the box below. Rotate
the eye back towards the image reflected from the mirror at about 325
degrees. Sketch the image of the candle that you see in the mirror.
Candle as seen directly
124 Convex Mirror Images
Candle as seen in mirror
© Pearson Education, Inc. All rights reserved.
2. The laboratory will be set up with a candle on an optics table with a convex
mirror in front of it. A detector, or virtual eye, is also placed on the table so
it can look at the candle reflection in the mirror. You will observe the image
of the candle from various distances and also observe the image of a beach
ball to determine how images are changed in a convex mirror.
sx07CAGr8_VPhyLab_46.fm Page 125 Tuesday, August 14, 2007 8:24 AM
Name ___________________________
Date ___________________
Class ____________
5. When light hits a convex mirror, it appears that it is all directed forward
into a point on the other side of the mirror called a focal point. Like a plane
mirror, all of the images seem to diverge from the other side of the mirror,
although really no light can go through the mirror. We will investigate the
size of the images produced and their orientation. Since light does not
actually pass through the mirror, the image is referred to as a virtual image.
6. Now you will click on the object and drag it closer to the mirror. Observe
the image of the candle. How did the image change when you moved the
object?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Convex Mirror Images
7. Keep pulling the object forward and observe the orientation and size of the
image as you approach the mirror. What happens to the orientation and
size of the image? Note the Height Factor displayed in the bottom of the
detector screen. This is the magnifying factor of the image from the original
size of the object.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
8. Rear view mirrors say “Objects in mirror are closer than they appear.”
Investigate why they would say that. What properties have you observed
that make objects seem farther away than they actually are? Think about
how objects at a distance appear in normal plane mirrors.
_________________________________________________________________
_________________________________________________________________
© Pearson Education, Inc. All rights reserved.
_________________________________________________________________
9. Controlling Variables Experiment with moving the object and keeping the
eye position constant, and then keep the object position constant and move
the eye position. Report your observations about size and orientation.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Convex Mirror Images
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sx07CAGr8_VPhyLab_47.fm Page 126 Tuesday, August 14, 2007 9:03 AM
Name ___________________________
Date ___________________
Class ____________
Lab 47: Looking at Images
Problem
To determine how an image is affected by the distance the object is from
the lens
Background
How many movies have you seen in a theater this past month? Did you know
that the film for the movie is placed in the projector upside down? Projectors
have convex lenses inside which flip the image on the film and magnify it so it
can be projected up on a screen a long distance away. Where there is a need to
magnify smaller objects or shrink larger ones, convex lenses are often used.
Convex lenses are used in applications such as in glasses for farsighted people,
in cameras, and in lighthouses. Because of their unique uses, these lenses are
found in many applications in the world.
Skills Focus
Predicting, observing, drawing conclusions
Procedure
1. Start Virtual Physical Science and select Looking at Images from the list of
assignments. The lab will open in the Optics laboratory.
3. Predicting What do you think will happen to the image of the candle that
you see in the lens as the object moves closer and closer to the lens?
_________________________________________________________________
4. You will be placing the object at different distances from the lens, and then
using the eye as a detector on the far side of the lens to find the location of
the image produced by the lens. There is only one point at which an image
is truly in focus. Turn off the autofocus feature in the detector screen by unchecking the Auto focus box. Move the detector eye until the image is in
focus. In the data table record the distance from the lens to the image.
Record the Height Factor displayed in the bottom of the detector screen.
This is the magnifying factor of the image from the original size of the
object. Repeat the experiment for all of the different distances of the object
from the lens as shown in the Data Table.
126 Looking at Images
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Looking at Images
2. The laboratory will be set up with a candle on an optics table with a convex
lens in front of it. An eye will be on the other side of the lens so it can look
at the image produced by the candle through the lens. You will observe the
image of the candle from various distances to determine how images are
changed in a convex mirror.
sx07CAGr8_VPhyLab_47.fm Page 127 Tuesday, August 14, 2007 9:03 AM
Name ___________________________
Date ___________________
Class ____________
Data Table
Distance of
object from
lens (in.)
26
20
16
12
6
Distance of
image from
lens (in.)
Inverted
(yes/no)
Image bigger
or smaller
than object?
Height
Factor
5. For all the experiments where the object is farther away than the focal point
of the lens, the image is on the opposite side of the lens as the object.
However, when the object is closer to the lens than the focal point, the
image is actually on the same side of the lens as the object. A common
example of this is with a magnifying glass being used to magnify
something. You look in the magnifying glass and see the image of the object
bigger than it actually is, on the same side of the lens as the actual object.
Predicting What do you think an object at the focal point of the lens will
produce?
_________________________________________________________________
6. Move the object to the focal point of the lens, which is located at 8 in. (or 4
pins from the lens). Sketch the image and record the distance. Did you get
what you predicted? What is a characteristic of convex lenses that you
observe here?
_________________________________________________________________
Looking at Images
Analyze and Conclude
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7. When objects are very far away, what does the image look like?
_________________________________________________________________
8. What happens when the object is located between the focal point and the
lens?
_________________________________________________________________
9. If you didn’t know the focal point of a convex lens, how might you be able
to discover it?
_________________________________________________________________
Looking at Images
127
sx07CAGr8_VPhyLab_48.fm Page 128 Tuesday, August 14, 2007 9:21 AM
Name ___________________________
Date ___________________
Class ____________
Lab 48: Ohm’s Law
Problem
To develop the relationship among voltage, current, and resistance by
manipulating these variables in electric circuits and examining the effects
Background
The unit for resistance—the ohm—is named after Georg Ohm, a German
scientist. Ohm hypothesized that resistance reduces the voltage, or the
potential difference between different parts of an electric field. He published
his research in 1826, but his findings were not accepted immediately. Ohm
found the mathematical relationship among voltage, current, and resistance,
which is widely used today.
Skills Focus
Controlling variables, drawing conclusions, understanding models
Procedure
1. Start Virtual Physical Science and select Ohm’s Laws from the list of
assignments. The lab will open in the Circuits laboratory.
3. First learn about the components that you will be using. Check the value of
the voltage source labeled on the battery pack above the breadboard.
Record your answer in Data Table 1. Do the same for the resistor
component by looking at the schematic on the engineering paper to the left
or by mousing over the resistor.
Ohm’s Law
4. An ammeter is connected to the resistor to measure the current (amps) that
is going through the circuit. The ammeter is part of the yellow multimeter
on the top right side of the table. Record the current shown on the ammeter
in the table.
5. To understand the relationship among these three variables, you will hold
one constant and change another to see the effect. Start with controlling the
voltage variable. This means you won’t change the voltage as you adjust
the other variables. Change the resistance of the resistor by right clicking
on the resistor and entering a value of 10. Record the new current through
the circuit. Continue changing the resistor as indicated in the table and
record the current and voltage in each case.
128 Ohm’s Law
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2. The laboratory will be setup with a voltage source and a resistor attached
to the breadboard. A breadboard is a reusable circuit board, which allows
you to connect components of a circuit by plugging the pieces into the
board and knowing which parts of the board are internally connected to
each other. The voltage source will be turned on and the resistor will be
attached to the source.
sx07CAGr8_VPhyLab_48.fm Page 129 Wednesday, August 15, 2007 7:42 AM
Name ___________________________
Date ___________________
Class ____________
Data Table 1
Resistance (R)
Voltage (V)
1
1.5
10
1.5
100
1.5
1000
1.5
10000
1.5
Current (A)
6. Now you will change the voltage and control the resistance to see how this
affects the measured current. Start with a 100 ohm resistor and change the
voltage source through all of the allowable voltages. Record your data in
Data Table 2.
Data Table 2
Resistance (R)
Voltage (V)
100
1.5
100
3
100
4.5
100
9
100
12
Current (A)
7. What happened to the current in the circuit when you increased the
resistance?
8. What does it mean if increasing the resistance affects the current—what is
going on electrically? What could happen if the resistance is increased too
much?
9. What happened to the current in the circuit when you increased the voltage
in the circuit?
10. A circuit can be modeled like a flowing river. What would represent
voltage sources, resistors, and current in the river example? Think about
how they each affect the flow of the river.
Ohm’s Law
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Analyze and Conclude
11. We can represent the current as I = V/R. Does this equation model your
findings? Support your answer from your data.
Ohm’s Law
129
sx07CAGr8_VPhyLab_49.fm Page 130 Monday, August 20, 2007 1:02 PM
Name ___________________________
Date ___________________
Class ____________
Lab 49: Circuit Diagrams
Circuit Diagrams
Problem
Understand the meanings of the different symbols in circuit diagrams and
learn how to create and use them
Background
An electric circuit diagram is a symbolic drawing showing the elements of an
electric circuit. The diagrams are drawn to make it easy to see the whole path
through which a current is flowing, through all of the different parts of a
circuit. Circuit diagrams can look like very complex mazes of wires and
symbols. However, if you learn to break them down piece by piece, they will
make sense. Knowing how to interpret circuit diagrams will help you
understand how your house is wired and how simple electrical devices like
flashlights and blow dryers work.
Skills Focus
Understanding procedures, relating concepts
Procedure
1. Start Virtual Physical Science and select Circuit Diagrams from the list of
assignments. The lab will open in the Circuits laboratory.
3. You will first build a circuit with a light bulb and a battery in series. You
will be drawing the diagram on the pad of paper, which will automatically
pull those actual elements out onto the breadboard and you will see the
circuit being built as you draw it.
a. On the pad of paper, grab and drag battery symbol and place
it on the right hand side of the paper. The battery symbol has
two small parallel lines labeled + and - and has two lines
representing wires at right angles with the parallel lines coming
out from the sides.
b. Now find a light bulb symbol and place it on the pad to the
left of the battery. This looks like an x in the middle of a circle.
c. Connect one end of the light bulb to positive terminal of the battery by
clicking and dragging the blue spot on the resistor to the green spot on
the positive end of the battery.
d. Attach the other end of the light bulb to the negative end of the battery.
e. Now click the number above the light bulb and change its value to 100w.
130 Circuit Diagrams
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2. The laboratory will be set up with all of the components in the boxes at the
bottom of the table. Nothing will be on the breadboard, which is the board
with holes in the middle of the table that we use to build circuits on. You
will need to follow the instructions below to determine how to place the
components on the diagram. You will also check to see if you correctly
placed the components.
sx07CAGr8_VPhyLab_49.fm Page 131 Monday, August 20, 2007 1:02 PM
Name ___________________________
Date ___________________
Class ____________
f. Increase the voltage from the battery by clicking on the arrow next to the
power button on the battery controller at the top.
Circuit Diagrams
g. You should see the light bulb assembled on the breadboard. If you
connected your wires correctly, then the light bulb should be lit.
4. You will now build a circuit with a light bulb and an oscillating power
source.
a. On the pad of paper, grab and drag the function generator
symbol and place it on the right hand side of the paper. The
function generator symbol is a circle with a sine wave symbol
inside and has two lines representing wires coming out from the sides.
b. Now place a light bulb symbol on the pad to the right of the
function generator.
c. Connect one end of the light bulb to the positive terminal of the function
generator as you did in Step 3c above.
d. Attach the other end of the light bulb to the negative end of the function
generator.
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e. You should see the light bulb assembled on the breadboard. If you
connected your wires correctly, then the light bulb should be lit. You will
probably need to adjust the frequency on the function generator until
you see the light bulb fade on and off as the voltage gradually increases
and decreases. At what frequency do you see the light bulb blinking?
5. Now play around with building a circuit with the different batteries, light
bulbs, capacitors, and inductors available. You will want to make sure your
light bulb will light, but you can wire it however you want to. You must
have 4 elements in your circuit.
Draw your circuit diagram in the box below and describe what happens
when you connect the circuit. For example, does your bulb flash, does it
blow out, does it start out lit, then turn off? You might need to change the
amount of resistance, capacitance, and inductance from the default values.
You do this by clicking on the label for each component and entering the
amount. Here are some sample values if you need suggestions on
component values: R1 100 , C1 0.1F, L1 .001H.
Circuit Diagrams
131
sx07CAGr8_VPhyLab_49.fm Page 132 Monday, August 20, 2007 1:02 PM
Date ___________________
Class ____________
Circuit Diagrams
Name ___________________________
Circuit diagram
Describing What happens in your circuit?
__________________________________________________________________
__________________________________________________________________
Analyze and Conclude
6. Some people think it is easier to build circuits just by moving around the
components on the breadboard. However, as you have probably seen, that
can get really messy with wires connecting all over the place. What is the
advantage to planning circuits with a diagram?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
8. When would it be important to have a circuit diagram?
__________________________________________________________________
__________________________________________________________________
9. In your life, where have you used something similar to a circuit diagram?
__________________________________________________________________
__________________________________________________________________
132 Circuit Diagrams
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7. Describe how you can tell where the current is flowing in a circuit diagram.
__________________________________________________________________
sx07CAGr8_VPhyLab_50.fm Page 133 Tuesday, August 14, 2007 9:29 AM
Name ___________________________
Date ___________________
Class ____________
Lab 50: Building Electrical Circuits
Problem
To construct series and parallel circuits and measure the voltage and current
through each type of circuit
Background
Building Electrical Circuits
Electronic devices like your computer or video game system require a certain
amount of electrical current to operate. The amount of current necessary can be
determined easily by the principles of electronics. If we obey these principles
the devices will work just fine; if not, they won't function properly. Before
building an electrical circuit for a device, you must first know all about the
device you are trying to build. You need to know if you can use series or
parallel connections to control the current for the device. As you will learn in
this lab, there are benefits to both kinds of connections. In this lab you will
study each type and learn the different applications of series and parallel
circuits.
Skills Focus
Interpreting data, drawing conclusions, developing hypothesis, relating differences
Procedure
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1. Start Virtual Physical Science and select Building Electrical Circuits from the
list of assignments. The lab will open in the Circuits laboratory.
2. The laboratory will be set up with all of the components in the storage
compartments at the bottom of the screen. Nothing will be on the
breadboard. You will need to follow the instructions below to determine
how to place the components on the diagram. Remember that a breadboard
consists of rows and columns that are connected to each other by metal
strips on the under side. The holes in the columns between the red and blue
strips are connected only to the other holes in their particular column. The
top column, by the red strip is for the + voltage source and the other
column is for the - voltage source. The holes in the rows in the middle of
the board are connected to each other and are labeled 1 through 25 with
two separate sets of rows. That means that all of the holes labeled a–e in the
row labeled 1 are connected to each other, as are all the a–e holes in row 2,
but those rows aren’t connected to each other. Follow the instructions
below to build the appropriate circuits.
3. You will first build a simple DC light bulb series circuit on the breadboard.
You will build it in phases and examine each phase as you go along.
Building Electrical Circuits
133
sx07CAGr8_VPhyLab_50.fm Page 134 Wednesday, August 15, 2007 7:43 AM
Name ___________________________
Date ___________________
Class ____________
Phase 1: One Light Bulb
a. Grab and drag out a small light bulb and place it on the breadboard with
one prong in hole 10b and place the other prong in hole 15b. Notice that
the wires connecting the voltage source to the breadboard. One wire goes
to the positive input column and one goes to the negative input thus
completing the circuit. You need to bring a new wire from the box and
connect it from the positive red column to the row where your light bulb
is attached, and place it into 1a. Bring another wire from 15a over to the
negative blue column.
b. Record in the table if the light bulb lights or not. It should light, so rewire
the circuit if you need to, to make sure everything connects.
Building Electrical Circuits
Phase 2: Two Light Bulbs in series
c. Bring out another small light bulb and connect it in series with the first
light bulb by placing one prong of the second light bulb into hole 15c and
the other into hole 20c. Then move the wire connecting the negative
terminal from 15a to 20a so that the circuit is complete.
d. Record in the table if both light bulbs light and rate their brightness
relative to how bright the single light bulb was.
Phase 3: Three Light Bulbs in series
e. Now add another light bulb from hole 20d to 25d.
f. Move the negative terminal wire from hole 25a to 25a so the circuit is
complete.
g. Record in the table if all three light bulbs light and rate their brightness
again.
h. Pull out one of the bulbs, but don’t change any of the other wires and
record what happens.
Data Table 1: Series Circuit
Phases
Lights?
Brightness
Two Light Bulbs
Three Light Bulbs
4. You will now build a simple parallel DC circuit. You will build it in phases
and examine each phase as you go along.
Phase 1: Two Light Bulbs in parallel
a. Remove the third light bulb and place it back into its box.
b. Move the second light bulb to be in holes 10e and 15e respectively.
134 Building Electrical Circuits
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One Light Bulb
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Name ___________________________
Date ___________________
Class ____________
c. Move the negative terminal wire from 25a to be in 15a so that the circuit
will be complete.
d. Record in the table if both light bulbs light and rate their relative
brightness as compared to just one light bulb.
Phase 2: Three Light Bulbs in parallel
e. Now add another light bulb into holes 15d and 10d respectively.
f. Record in the table if all three light bulbs light and rate their relative
brightness as compared to just one light bulb and compared to the 2 light
bulbs.
g. Pull out one of the bulbs, but don't change any of the other wires and
record what happens.
Data Table 2: Parallel Circuit
Lights?
Building Electrical Circuits
Resistor Number
Brightness
Two Light Bulbs
Three Light Bulbs
Analyze and Conclude
5. Analyze In the series circuit what characteristic was common throughout
the experiment? What changed as you added more light bulbs?
__________________________________________________________________
__________________________________________________________________
6. Analyze In the parallel circuit what characteristic was the same
throughout the experiment?
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
__________________________________________________________________
7. Conclude From questions 5 and 6, why would knowing these
characteristics of circuits be important in designing electrical circuits?
__________________________________________________________________
__________________________________________________________________
8. If you wanted to check to see if a set of Christmas lights were connected in
series or parallel how could you do this?
__________________________________________________________________
__________________________________________________________________
Building Electrical Circuits
135
sx07CAGr8_VPhyLab_50.fm Page 136 Tuesday, August 14, 2007 9:29 AM
Name ___________________________
Date ___________________
Class ____________
9. Name two examples of series circuits. Name one example of parallel circuit.
__________________________________________________________________
__________________________________________________________________
10. Extension Activity Connect two light bulbs in series with a power source.
Then add a light bulb in parallel with the first light bulb. What happens to
the brightness of the bulb that is in series with the two parallel bulbs? What
happens when you have 3 bulbs in parallel and then the one bulb in series
with that whole combination? Why do you think the brightness changes as
you see?
__________________________________________________________________
Building Electrical Circuits
__________________________________________________________________
© Pearson Education, Inc. All rights reserved.
136 Building Electrical Circuits
sx07CAGr8_VPhyLab_51.fm Page 137 Tuesday, August 14, 2007 9:41 AM
Name ___________________________
Date ___________________
Class ____________
Lab 51: Making Observations of
Our Solar System
Purpose
To investigate the motion of Earth and the other objects in the solar system
Background
It’s hard to appreciate the magnitude or size of the solar system. The masses of
the planets and other objects, the sizes of their orbits, and the speeds at which
they travel are amazing. In order to gain some understanding, you can relate
the motion of the objects to things you can understand, for example, the time it
takes Earth to go around the sun (one Earth year). Then you can compare other
objects to Earth. In this assignment, you will make qualitative observations
about the solar system.
Skills Focus
Observing, predicting, drawing conclusions
Procedure
1. Start Virtual Physical Science. Select Making Observations of Our Solar System
from the list of assignments. The lab will open in the Mechanics laboratory.
Making Observations
of Our Solar System
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2. The laboratory is set up in the Solar System View with the sun in the middle.
The inner planets (not to scale) are in their orbits. The outer planets, Pluto,
and a comet are in the transfer table. You can click on the Start button to see
the inner planets (Mercury, Venus, Earth and Mars) begin to orbit in their
individual paths around the sun. Click Pause when you have finished
observing. Click Reset.
3. Observing The planets move in their orbits at different speeds. The time it
takes a planet to make one trip around the sun is called the period of its
orbit. The Time display gives the current time for the solar system in
year:day format. The experiment starts on the current day of the year which
is shown in the Time display. Choose a planet to watch first. Click the Start
button and watch the planet. When the planet returns to the start of its orbit,
click Pause. In the second column of the table on the next page, record the
Time display at the end of one orbit. You can speed up or slow down the
process using the Time Acceleration buttons.
To calculate the period of one orbit, first subtract the initial year at the
beginning of the orbit from the year after one orbit. Then divide the number
of days by 365. This is a fraction of an Earth year. Add the whole number of
years to the fraction to get the total period. Record this number in the last
column of the table. Click Reset and repeat the procedure for each remaining
object.
To find the periods of the outer planets, Pluto, and the comet, drag them
from the transfer table to the work area.
Making Observations of Our Solar System
137
sx07CAGr8_VPhyLab_51.fm Page 138 Tuesday, August 14, 2007 9:41 AM
Name ___________________________
Object
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Comet
Date ___________________
Time Display at the End
of One Orbit (year:day)
Class ____________
Period of One Orbit
(in Earth years)
4. Observing What general difference do you observe between the inner
planets and the outer planets (those farther away from the sun than Mars)?
What is different about the orbit of Pluto? What differences do you observe
about the orbit of the comet?
__________________________________________________________________
__________________________________________________________________
5. Predicting From your view of the solar system, it looks as if the comet
could collide with the other objects. Why do you think this doesn’t happen
very often?
__________________________________________________________________
__________________________________________________________________
6. Drawing Conclusions Change the view of the solar system by clicking on
the Parallel View button. You can now view the motion of the objects from
the side view or the plane of the orbits. Notice that most of the objects move
in the same plane, but the orbits of Pluto and the comet are tilted at an angle
from the plane of the planets. How does this support your answer in Step 5?
__________________________________________________________________
__________________________________________________________________
7. Observing Change the view that you are looking at by clicking on the
Object View button on the side. Click on each object to observe its moons.
Only the major moons of each object are displayed. Which objects have the
most moons? Are there any objects that do not have moons orbiting them?
__________________________________________________________________
8. Note one thing you have observed about the solar system that you did not
know before.
__________________________________________________________________
138 Making Observations of Our Solar System
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Making Observations
of Our Solar System
__________________________________________________________________
sx07CAGr8_VPhyLab_52.fm Page 139 Tuesday, August 14, 2007 9:48 AM
Name ___________________________
Date ___________________
Class ____________
Lab 52: Tracking the Phases of the Moon
Purpose
To investigate the phases of the moon
Background
Sometimes, on cloudless nights, you might go outside and enjoy the light of the
sun by its reflection off the surface of the moon. Probably you have noticed that
on different nights the moon has a different shape. Its shape varies from full
moon (fully round) to new moon (no light) depending on the time of the
month. The shape of the illuminated part of the moon at any time of the month
is called the phase of the moon. In this assignment you will discover why the
moon has different phases.
Skills focus
Predicting, observing, drawing conclusions
Procedure
1. Start Virtual Physical Science. Select Tracking the Phases of the Moon from the
list of assignments. The lab will open in the Mechanics laboratory.
2. The virtual laboratory is set up in the Top Planet View. In this view you can
look at the Earth-Moon system. Earth is in the middle of the screen. The
sun’s rays are coming from the top of the screen.
3. Click the Start button and watch as the moon orbits Earth. Use the Time
Acceleration buttons to speed time up and slow time down. Observe the
motion of the moon for one month (30 days).
Predicting What do you think causes the phases of the moon?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
4. Click on the Reset button to reset the experiment. Repeat the experiment to
make specific observations. This is approximately the way things are
oriented on the current day. On Diagram 1a, sketch what the moon looks
like from above. Click on the Inside Object View button to observe the moon
from Earth. Sketch what you see in Diagram 1b. Use the Rotate Around
Object button if the moon is not in the viewing area, until you see the moon.
Tracking the Phases of the Moon
Tracking the Phases
of the Moon
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_________________________________________________________________
139
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Name ___________________________
Date ___________________
Class ____________
Diagram 1
a.—View from above b.—View from Earth
Moon
Sun
5. Return to the Top Object View and advance the time to 7 days. Observe what
the moon looks like. On Diagram 2a, sketch what the moon looks like from
above. Click on the Inside Object View button to observe the moon from
Earth. Sketch what you see in Diagram 2b.
Diagram 2
a.—View from above b.—View from Earth
Moon
Sun
Diagram 3
Tracking the Phases
of the Moon
a.—View from above b.—View from Earth
Moon
Sun
140 Tracking the Phases of the Moon
© Pearson Education, Inc. All rights reserved.
6. Return to the Top Object View and advance the time to 7 more days. Observe
what the moon looks like. On Diagram 3a, sketch what the moon looks like
from above. Then click on the Inside Object View button to observe the
moon from Earth. Sketch what you see in Diagram 3b.
sx07CAGr8_VPhyLab_52.fm Page 141 Tuesday, August 14, 2007 9:48 AM
Name ___________________________
Date ___________________
Class ____________
7. Return to the Top Object View and advance the time 7 more days. Observe
what the moon looks like. On Diagram 4a, sketch what the moon looks like
from above. Then click on the Inside Object View button to observe the
moon from Earth. Sketch what you see in Diagram 4b.
Diagram 4
a.—View from above b.—View from Earth
Moon
Sun
8. Return to the Top Object View and advance the time to 8 more days. Observe
what the moon looks like. On Diagram 5a, sketch what the moon looks like
from above. Click on the Inside Object View button to observe the moon
from Earth. Sketch what you see in Diagram 5b.
Diagram 5
Tracking the Phases
of the Moon
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a.—View from above b.—View from Earth
Moon
Sun
Tracking the Phases of the Moon
141
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Name ___________________________
Date ___________________
Class ____________
9. In Diagram 6 the moon is shown in four different locations around Earth
relative to Earth. These locations correspond to various days in a month.
Indicate approximately which days these correspond to what you have
examined.
10. Remember what you observed in Steps 4–8. Half of the moon is always
illuminated by the sun. Sketch this in Diagram 6.
Diagram 6
Analyze and Conclude
1. Drawing Conclusions Use your sketches of the moon at different times of
the month to explain why the moon has different phases.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Tracking the Phases
of the Moon
142 Tracking the Phases of the Moon
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2. Was your prediction about the cause of the phases of the moon correct? Why
or why not?
__________________________________________________________________
sx07CAGr8_VPhyLab_53.fm Page 143 Tuesday, August 14, 2007 9:50 AM
Name ___________________________
Date ___________________
Class ____________
Measuring the Orbital Speed
of the Planets
Lab 53: Measuring the Orbital Speed
of the Planets
Purpose
To determine how fast Earth and the other planets are moving
Background
When you are traveling fast in a car, objects along the roadside appear to move
by quickly. But when you travel in an airplane, objects that you see below seem
to move more slowly, even though the plane is moving faster than the car. Why
is this? Every day Earth turns around or rotates once on its axis. This is what
causes the sun to move across the sky. But besides rotating, Earth is also
moving in its orbit around the sun. This motion takes a year, but you don’t
even notice it. In this assignment you will determine the speed of Earth in its
orbit and come to appreciate how fast you are actually moving.
Skills Focus
Observing, predicting, calculating, drawing conclusions, relating cause and
effect
Procedure
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1. Start Virtual Physical Science. Select Measuring the Orbital Speed of the Planets
from the list of assignments. The lab will open in the Mechanics laboratory.
2. The laboratory is set up in the Solar System View with the sun in the middle.
You will see the inner planets (not to scale) in their orbits. Click on the Start
button. The planets will begin to move in their orbits around the sun. Click
Pause when you have finished observing. Each planet moves at a different
speed in its orbit. You can calculate their speeds by using the formula:
Speed Distance
------------------Time
Predicting Approximately how fast do you think Earth is traveling in its
orbit?
__________________________________________________________________
3. You will first measure the distance from the sun to each planet in the solar
system. A planet’s distance from the sun is called the radius of orbit. Click
on each planet and record, in the table below, the radial distance from the
sun. This distance is displayed below the experiment window where it has a
value for r. You will use the radius of orbit to estimate the circumference or
length of each planet’s orbit. The displayed radius is the radius at the given
day, which could be larger or smaller than the average radius. The planets’
orbits are ellipses rather than circles, but a good approximation can be made
by considering them to be circles. Recall that the formula for the
circumference of a circle is C2πR where C is the circumference and R is the
radius. Calculate the circumference of each planet’s orbit and record it in the
table.
Measuring the Orbital Speed of the Planets
143
sx07CAGr8_VPhyLab_53.fm Page 144 Tuesday, August 14, 2007 9:50 AM
Measuring the Orbital Speed
of the Planets
Name ___________________________
Date ___________________
Class ____________
4. Observing The amount of time it takes for each planet to travel once
around its orbit is called its period. Click the Reset button to return all
planets to their original positions. To record the period of each planet, click
the Start button. Watch one of the planets. Click Pause when the planet
returns to the position it started from. To calculate the period in years,
divide the number of days elapsed by 365. This is a fraction of a year. Add
the whole number of years that passed to this fraction to get the total period.
Record in the table the time it took to orbit. Click Reset to reset the time clock
and repeat the experiment for each planet. You will want to accelerate time
in the time window by using the Time Acceleration buttons. Add the
remaining planets, as well as Pluto and the comet, from the tray to the work
area. Collect the same data for these objects too.
Table
Object
Radius of
Orbit
(AU)
Circumference
of Orbit
(AU)
Period
(years)
Orbital
Speed
(AU/year)
Orbital
Speed
(miles/
hour)
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Neptune
Pluto
Comet
Analyze and Conclude
1. Calculating Calculate the orbital speed of each planet by dividing the
distance it travels in its orbit by the period. The units of your answer should
be AU/year. Record your answers in the table.
2. Calculating Multiply the orbital speed you just calculated by 10604. This
changes a speed in AU/year to miles/hour. (This conversion works because
1 AU/year 10,604 miles/hour.) Record your answers in the table. Is this
fast?
__________________________________________________________________
3. Drawing Conclusions Why don’t you feel as if you are moving this fast?
__________________________________________________________________
4. Relating Cause and Effect If Earth is really going as fast as you calculated
it is, why doesn’t the planet fly out of its orbit into space?
__________________________________________________________________
144 Measuring the Orbital Speed of the Planets
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Uranus
sx07CAGr8_VPhyLab_54.fm Page 145 Tuesday, August 14, 2007 9:52 AM
Name ___________________________
Date ___________________
Class ____________
Lab 54: How Strong is Gravity?
Problem
To compare the gravitational forces on different planets and moons in the solar
system
Background
The English scientist Isaac Newton realized that gravity acts everywhere in the
universe, not just on Earth. Gravity is the force that makes an apple or any
other object fall to the ground. It is the force that holds you firmly on Earth’s
surface so that you don’t fly off into space. It is the force that keeps the moon
orbiting around Earth. It is the force that keeps all the planets in our solar
system orbiting around the sun. In this lab you will visit some of the planets or
moons in the solar system and observe how the acceleration due to gravity
differs depending on where you are.
How Strong is Gravity?
Skills Focus
Interpreting data, graphing, drawing conclusions, applying concepts
Procedure
1. Start Virtual Physical Science. Select How Strong is Gravity? from the list of
assignments. The lab opens in the Mechanics laboratory.
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2. The laboratory is set up with a ball at the top of the experiment window,
30 m above the surface. This is about as high as a nine story building.
Gravity, which is set the same as on Earth, will pull the ball downward. You
will observe how long it takes the ball to fall to the ground. The mass of the
ball is 1 kg.
3. Click on the Lab Book to open it. Click on the red Recording button to start
recording data. Start the experiment by clicking on the Start button and
observe what happens. When the ball reaches the bottom, the experiment
will stop and you should see a link appear in the Lab Book. This contains the
velocity versus time data for the falling ball.
4. Click the Reset button to reset the experiment. Use the Gravity tab under the
Parameters Palette to select a different planet, which will have a different
gravity. Repeat Step 3 to record the velocity of the ball as it falls. Do this on
four different planets or moons. Try a big planet such as Jupiter and a small
body such as Earth’s moon.
How Strong is Gravity?
145
sx07CAGr8_VPhyLab_54.fm Page 146 Tuesday, August 14, 2007 9:52 AM
Name ___________________________
Date ___________________
Class ____________
5. Use the data in each of the data links in the Lab Book to fill in the tables
below. You will need the speeds of the balls, so open the velocity versus time
links for each planet or moon. In each of the tables, record the speed (make
the velocity positive) at the nearest time interval for the first three seconds.
Table 1
Planet
Earth
Time (s)
Speed (m/s)
0
0.5
1.0
1.5
How Strong is Gravity?
2.0
2.5
3.0
Table 2
Table 3
Planet
Time (s)
Planet
Speed (m/s)
Time (s)
0
0.5
0.5
1.0
1.0
1.5
1.5
2.0
2.0
2.5
2.5
3.0
3.0
Table 4
Table 5
Planet
Time (s)
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0
Speed (m/s)
Planet
Speed (m/s)
Time (s)
0
0
0.5
0.5
1.0
1.0
1.5
1.5
2.0
2.0
2.5
2.5
3.0
3.0
146 How Strong is Gravity?
Speed (m/s)
sx07CAGr8_VPhyLab_54.fm Page 147 Tuesday, August 14, 2007 9:52 AM
Name ___________________________
Date ___________________
Class ____________
Analyze and Conclude
1. Graphing For each experiment, use the data in the tables to draw a speed
versus time graph on the grid below. Label the horizontal axis Time (s) and
the vertical axis Speed (m/s). Scale the graph to fit your data. The first data
point will always be (0 s, 0 m/s). Connect the data points using different
colored pencils for each planet or moon. Label each line with the name of the
planet or moon.
How Strong is Gravity?
2. Interpreting Data How does the speed at which the balls fall vary from
planet to planet?
__________________________________________________________________
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On which planet did the ball fall the fastest? On which planet did the ball
fall the slowest?
__________________________________________________________________
3. Applying Concepts What does the constant slope of each of the graphs
tell you about the motion of the ball?
__________________________________________________________________
4. Drawing Conclusions Which planet has the strongest gravity?
__________________________________________________________________
Going Further
5. Calculate the gravitational acceleration of the planet that you said has the
strongest gravity. Remember that the slope of a speed or velocity graph is
the acceleration. (Slope = Rise/Run, Acceleration = Change in velocity/Change
in time). Earth’s gravitational acceleration is 9.8 m/s/s. How much stronger
is gravity on your planet than on Earth?
__________________________________________________________________
__________________________________________________________________
How Strong is Gravity?
147
sx07CAGr8_VPhyLab_55.fm Page 148 Tuesday, August 14, 2007 9:59 AM
Name ___________________________
Date ___________________
Class ____________
Lab 55: Why Pluto is Not a Planet
Purpose
To learn why scientists reclassified Pluto
Background
According to the new definition accepted by astronomers, a true planet is an
object that orbits the sun and is large enough to have become round due to the
force of its own gravity. In addition, a planet has to be bigger than all the other
objects around its orbit. Pluto has been demoted from a planet to a “dwarf
planet” because it does not dominate in the area around its orbit. Charon, its
large "moon," is only about half the size of Pluto, while all the true planets are
far larger than their moons.
Skills Focus
Observation, Interpreting observations, Drawing comparisons, Ranking
Procedure
1. Start Virtual Physical Science and select Why Pluto is Not a Planet from the
list of assignments. The lab will open in the Mechanics laboratory. The
laboratory will be set up in a simulation of the solar system, zoomed down
to where you can see all the planets of the solar system and Pluto.
3. Find the mass of Mercury. On the Parameters Palette click on the icon of
Mercury. Record the mass of Mercury in table 1.
4. Find the Orbital Inclination. The inclination is the amount of tilt that the
orbit of the planet, including Pluto, is tilted with respect to the orbit of the
Earth. So, if the object has an inclination of 7°, then its orbit is tilted by 7°
from the orbit of Earth. In the Object section of the Parameters Palette find
the inclination of Mercury and record it in table 1.
5. Find the average orbital radius, which is the average distance that the
planet (including Pluto) orbits away from the Sun. To determine an
average orbital radius, choose four different locations in the orbit and
record the distance from the Sun. First click on a planet or Pluto in the Solar
System View to have the data displayed in the data table below the
viewing screen. Find the radius labeled r. This is the radius from the Sun.
Record this radius in Table 2 Location 1. Click Start to start the object’s
orbiting and Pause when the object is in a different part of its orbit and
record the radius there. You will probably want to remove some of the
outer planets and Pluto to the tray at the top of the screen, so that you can
see the orbits of the inner planets better. It may also help if you accelerate
148 Why Pluto is Not a Planet
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Why Pluto is Not a Planet
2. Compare the planets using the information gathered from the Parameters
Palette and from the data displayed at the bottom of the screen. Fill in the
table with the appropriate information. The following instructions will
show how to gather the information. Repeat for all the planets and Pluto.
sx07CAGr8_VPhyLab_55.fm Page 149 Tuesday, August 14, 2007 9:59 AM
Name ___________________________
Date ___________________
Class ____________
time in the time control panel at the bottom left of the screen, to make the
time pass faster in the orbits. Click the + sign to make time go faster, and –
to slow it down. Choose three other locations in each orbit and record these
radii in Table 2.
6. Find the average of those four radii by adding them and then dividing by
four (the number of locations you choose). Use Table 2 to record the four
different radii. Then record your average in the Table 1.
Table 1: Observation Table
Object
Mass
Inclination
Average Orbital
Object
Radius
Radius (km)
Mercury
2.44 103
Venus
6.05 103
Earth
6.37 103
Mars
3.40 103
Jupiter
7.15 104
Saturn
6.03 104
Uranus
2.56 104
Neptune
2.48 104
Pluto
1.20 103
Table 2: Orbital Radius
Object
Location 1
Location 2
Location 3
Location 4
Why Pluto is Not a Planet
Mercury
Venus
Earth
Mars
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Jupiter
Saturn
Uranus
Neptune
Pluto
Analyze and Conclude
7. Ranking Using the data collected in the Observation Table, rank the
planets and Pluto from smallest to largest.
Why Pluto is Not a Planet
149
sx07CAGr8_VPhyLab_55.fm Page 150 Tuesday, August 14, 2007 9:59 AM
Name ___________________________
Date ___________________
Class ____________
Object Radius
Smallest
--------
--------
--------
Medium
-------
--------
---------
Largest
-------
--------
---------
Largest
-------
--------
---------
Largest
Mass
Smallest
--------
--------
--------
Medium
Inclination
Smallest
--------
--------
--------
Medium
8. Drawing conclusions How does Pluto’s orbital radius compare with
those of the planets’?
_________________________________________________________________
9. According to the ranking charts above, explain why reclassifying Pluto
according to these variables is a good decision.
_________________________________________________________________
10. Click on different planets and use the Object View button (concentric
circles with an arrow pointing in) to zoom down onto each planet and its
moons. Compare the motion and size of the other planets and their moons
to Pluto and its moon Charon. How do they compare? How do they differ?
_________________________________________________________________
_________________________________________________________________
11. Developing Opinion Do you agree or disagree with the reclassification?
Use data observation to explain your answer.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
150 Why Pluto is Not a Planet
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Why Pluto is Not a Planet
_________________________________________________________________
sx07CAGr8_VPhyLab_Answer.fm Page 151 Friday, September 7, 2007 7:00 AM
Answers
Lab 1—Introduction to Scientific Inquiry
1. A sample question might be: How does
the volume of a balloon change when
the temperature changes?
Analyze and Conclude
1. The balloon got larger as the
temperature was increased.
2. A sample hypothesis might be:
Increasing the temperature will increase
the volume of the balloon.
2. Temperature is on the horizontal axis
and volume on the vertical axis. The
graph is a straight line starting at 100°C
and 1531 cm3 and slopes upward to the
right.
3. Begin with a balloon filled with gas at a
certain temperature. Measure the volume
and then increase the temperature.
Compare the volume and temperature at
the higher temperature with the original
measurements to determine the effect of
changing temperature.
Temperature (°C); Volume (cm3); About
3000 cm3
The volume should be approximately
5200 cm3 when the temperature is
1000°C.
Temperature; Volume
Temperature (°C)
Volume
3. A sample answer might be: The
hypothesis stated that volume would
increase as temperature increased. The
data shows that the volume increases as
the temperature increases. The graph
confirms this conclusion. The
hypothesis was correct.
(cm3)
100
1531
200
1941
300
2352
400
2762
500
3172
600
3583
700
3993
Your TV report should include the six
steps in scientific inquiry and how they
relate to the experiment in this
assignment.
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Lab 2—Making Sense of Density
Ball
Mass of Ball
(g)
Volume of
Water (mL)
Volume of Water
and Ball (mL)
Volume of
Ball
Density
(g/mL)
Au
312.114
228
244.2
16.2
19.27
Al
47.713
228
245.2
17.2
2.66
Analyze and Conclude
1. The gold sample had more mass than
the aluminum sample because it was
more dense.
2. Answers will vary depending on how
much the students know about the
different materials. The lead would be
the most dense and the cork would be
the least dense. You could determine
this by measuring the mass and volume
of each object.
3. Yes, since the density of aluminum is
low, an airplane with the same amount
of metal would be lighter. The density of
an airplane is a factor in its ability to fly
and the cost of fuel.
Answer Key
151
sx07CAGr8_VPhyLab_Answer.fm Page 152 Friday, September 7, 2007 7:00 AM
Lab 3—Investigation of Gas Pressure and Mass
Mass (tons)
External Pressure
(psi)
Internal Pressure from
Meter (psi)
Calculated Internal
Pressure (psi)
0
14.7
14.7
0.5
14.7
51.2
51.3
2.5
14.7
197.3
197.8
Analyze and Conclude
6. They are very close.
1. 1000 lbs
7. 14.7 psi 183.1 psi 197.8 psi
calculated 197.8 psi; the meter reads
197.3 psi. The numbers are within
experimental error.
2. 7.5 cm
3. 27.3 in2
4. 36.6 psi
5. 14.7 psi 36.6 psi 51.3 psi, which is
essentially the same as the pressure on
the meter
The internal pressure for the car tire is
32 psi 14.7 psi 46.7 psi. This is only
one-fourth of the pressure calculated in 7.
Lab 4—Pressure and Volume of a Gas
2. As the pressure is increased the volume
decreases.
Volume (cm3)
100
7436
200
3718
300
2478
400
1859
500
1487
600
1239
700
1062
152 Answer Key
1. The graph is a curve sloping down from
the upper left. The line comes closer and
closer to a volume of 1000 cm3 as the
pressure approaches 700 kPa. The
volume is largest when the pressure is
the lowest.
2. The graph shows that as the pressure
increases the volume decreases.
3. Nonlinear
4. If the pressure were decreased, the
volume would increase because
pressure and volume vary indirectly.
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Pressure (kPa)
Analyze and Conclude
sx07CAGr8_VPhyLab_Answer.fm Page 153 Friday, September 7, 2007 7:00 AM
Lab 5—Pressure and Temperature of a Gas
2. As the temperature is increased the
pressure will increase.
Temperature (°C)
Pressure (kPa)
Analyze and Conclude
1. The graph is a straight line sloping
upward from the lower left to the upper
right.
100
310.3
200
393.4
300
476.5
2. Yes, the graph shows that as the
temperature increases, the pressure also
increases.
400
559.7
3. linear
500
642.8
600
726.0
700
809.1
4. If the temperature were decreased, the
pressure would also decrease because
temperature and pressure vary directly.
Lab 6—Changes Between a Solid and a Liquid
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1. Temperature is plotted on the vertical
axis and time is plotted on the
horizontal axis. The graph should
show that when the water cools down
the temperature of the water and ice
mixture is approximately 0°C. For
approximately 1.5 minutes the
temperature does not change. After
1.5 minutes, the temperature increases
gradually. The horizontal portion of the
graph should be labeled ice/water
mixture. The sloping line should be
labeled liquid.
2. liquid and solid
liquid
The temperature remains constant at 0°C.
This occurs when the ice is melting and
becoming liquid water. Normally, the
temperature increases as thermal energy
increases because the molecules move
faster, but during the change from solid to
liquid the molecules are breaking free
from each other and changing to a liquid
and the temperature stays constant.
The temperature begins to rise as
soon as all of the ice is melted. The
temperature rises because the thermal
energy of the molecules is increasing
causing them to move faster.
Answer Key
153
sx07CAGr8_VPhyLab_Answer.fm Page 154 Friday, September 7, 2007 7:00 AM
Lab 7—Changes Between a Liquid and a Gas
Temperature at Boiling
Pressure at Boiling
100.44°C
772 torr
1. The graph should be labeled
Temperature (°C) on the vertical axis
and Time (min) on the horizontal axis.
The line rises steeply to the right from
25°C at zero minutes to about 100°C
after about 1 minute. For the next three
minutes, the line is horizontal. The
portion of the line that is rising should
be labeled water. The horizontal portion
of the line should be labeled water and
water vapor.
2. Temperatures may vary around 100°C.
The temperature of the water increases
as heat is added. The temperature
increases because the water molecules
are given more thermal energy. As a
result they move faster and vibrate more.
The temperature remains constant
during the boiling process. This is
because the heat that is being added to
the water is being used to create water
vapor instead of raising the temperature.
Going Further
3. The boiling point is normally 100°C but
could have been higher or lower in the
virtual laboratory depending on the
pressure. An increase in air pressure
increases the boiling point. Lower air
pressure decreases the boiling point.
4. The boiling point of water is directly
related to air pressure. In the
experiment the air pressure could have
been higher, so the boiling point would
have been too. If the air pressure was
lower, the boiling point would have
been too, but at the top of Mt. McKinley
the air pressure would be much lower
so the boiling point would also be much
lower than 100°C.
Lab 8—Thomson and Smaller Parts of Atoms
2. Electron gun
3. A spot in the center of the phosphor
screen
4. The spot moves to the right.
154 Answer Key
In the center of the phosphor screen
6. 34 mT of magnetic field balances 10 V of
electric field and causes the spot to
return to the center.
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Negative; A phosphor screen
5. The spot moves to the left.
sx07CAGr8_VPhyLab_Answer.fm Page 155 Friday, September 7, 2007 7:00 AM
Lab 9—Rutherford and the Nucleus
2. Alpha particles
7. The hits show up every few seconds.
3. Gold
8. It takes nearly a minute for even a single
hit to appear.
4. Phosphor screen
5. Spots of light
Hits from alpha particles being
deflected at small angles
As the positively charged particles pass
through the gold atoms they are
attracted by the negatively charged
electrons and their path is slightly bent.
The alpha particles hit the screen at a
rapid rate.
6. The hits are not quite as frequent and
the forward scattering spot is no longer
visible.
9. The alpha particles would have to be
hitting a large mass in the center of
the atom. The mass of the gold atom is
not spread evenly throughout the atom.
It is concentrated in a central atomic
nucleus.
10. Mostly empty space
11. Most of the alpha particles came
straight through the foil or were only
slightly deflected. This evidence
suggests that the atom is mostly empty
space. But some alpha particles were
deflected at large angles. These
deflections could happen only if an
alpha particle came close to or hit a
large positive mass.
Lab 10—Elements and the Periodic Table
Symbol
Color of
Solution
Atomic
Number
Atomic
Mass
Group
Number
Silver
Ag
colorless
47
107.87
11
Sodium
Na
colorless
11
22.99
1
Potassium
K
colorless
19
39.10
1
Cobalt
Co
pink
27
58.93
9
Copper
Cu
blue
29
63.55
11
Chromium
Cr
purple
24
52.00
6
Magnesium
Mg
colorless
12
24.31
2
Barium
Ba
colorless
56
137.33
2
Calcium
Ca
colorless
20
40.08
2
Vanadium
V
green
23
50.94
5
Nickel
Ni
green
28
58.69
10
Aluminum
Al
colorless
13
26.98
13
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Element
Answer Key
155
sx07CAGr8_VPhyLab_Answer.fm Page 156 Friday, September 7, 2007 3:31 PM
Analyze and Conclude
1. The number of protons and the number
of electrons in an atom
2. 23 protons and 23 electrons
3. Because most elements consist of a
mixture of isotopes with different
atomic masses
4. Alkali metals: sodium and potassium
Alkaline-earth metals: barium,
magnesium, and calcium
Transition metals: silver, cobalt, copper,
chromium, vanadium, and nickel
Mixed group metals: aluminum
5. Elements in the transition metal group
are usually colored. Elements not in the
transition metal group are colorless.
Lab 11—Density of Solids and Liquids
5. Subtract the volume of the Virtual Fluid
from the total volume of the Virtual Fluid
and the plastic sample.
Table 1
Sample
Mass of
Sample (g)
Volume of
Virtual
Fluid (mL)
Volume of
Virtual
Fluid and
Sample
(mL)
Plastic
17.154
226.8
224
17.2
0.997
Volume of
Sample
(mL)
Density
(g/mL)
9. Subtract the mass of the empty beaker
from the mass of the beaker and the
alcohol.
Table 2
Mass of
Beaker and
Sample (g)
Mass of
Sample (g)
Volume of
Sample
(mL)
Density
(g/mL)
Alcohol
101.310
279.168
177.858
225.8
0.788
Analyze and Conclude
1. To determine the volume of the solid,
the solid must be completely covered by
the liquid. If part of it was sticking out
of the Virtual Fluid, the calculated solid
volume would be less than the actual
solid volume. The volume would be less
by the amount of volume sticking out of
the liquid.
2. Materials with a higher density than
water sink. Materials with a lower
density than water float.
156 Answer Key
3. The density of the plastic ball is
0.997 g/mL. The density of alcohol is
0.788 g/mL. Because the density of the
plastic is higher than the density of the
alcohol, the plastic would sink.
4. You would need to measure the mass
and the volume of each sample and
calculate the densities. A solid sample
will float in any liquid that has a higher
density and sink in any liquid that has a
lower density.
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Sample
Mass of
Empty
Beaker (g)
sx07CAGr8_VPhyLab_Answer.fm Page 157 Friday, September 7, 2007 7:00 AM
Lab 12—Creating Chemical Compounds
8. black
Test Tube
Formula from
Screen
Color Before
Color After
Ratio
1
AgCl
colorless
white
1:1
2
PbCl2
colorless
white
1:2
3
FeS
yellow
black
1:1
4
CuS
blue
black
1:1
5
PbS
colorless
black
1:1
6
Ag2S
colorless
black
2:1
Analyze and Conclude
2. No, both ions have positive charges.
1. 2–
3. SnCl4
Lab 13—Names and Formulas of Ionic Compounds
Observation Table
Ag+ silver
Pb2+ lead
Fe3+ iron
Cu2+ copper
Na2S (S2) sulfide
black
black
black
black
NaCl (Cl) chloride
white
white
NR
NR
Na2SO4 (SO42) sulfate
NR
white
NR
NR
NaOH (OH) hydroxide
pinkish
NR
red
dark blue
pink
white
red
blue/white
Ag+ silver
Pb2+ lead
Fe3+ iron
Cu2+ copper
Na2S (S2) sulfide
Ag2S
PbS
Fe2S3
CuS
NaCl (Cl) chloride
AgCl
PbCl2
NR
NR
Na2SO4 (SO42) sulfate
NR
PbSO4
NR
NR
NaOH (OH) hydroxide
AgOH
NR
Fe(OH)3
Cu(OH)2
Ag2CO3
PbCO3
Fe2(CO3)3
CuCO3
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Na2CO3 (CO32)
carbonate
Analyze and Conclude
Chemical Formula Table
Na2CO3 (CO32)
carbonate
Answer Key
157
sx07CAGr8_VPhyLab_Answer.fm Page 158 Friday, September 7, 2007 7:00 AM
Chemical Name Table
Ag+ silver
Pb2+ lead
Fe3+ iron
Cu2+ copper
Na2S (S2)
sulfide
silver sulfide
lead sulfide
iron sulfide
copper sulfide
NaCl (Cl)
chloride
silver chloride
lead chloride
NR
NR
NR
lead sulfate
NR
NR
NaOH (OH)
hydroxide
silver
hydroxide
NR
iron hydroxide
copper
hydroxide
Na2CO3
(CO32)
carbonate
silver
carbonate
lead carbonate
iron carbonate
copper
carbonate
Na2SO4
(SO42) sulfate
2. Calcium sulfide, magnesium hydroxide,
potassium hydroxide
Analyze and Conclude
1. Ag2SO4, PbSO4, Fe2(SO4)3
Lab 14—Describing Chemical Reactions
3. The solution was clear. When NaOH
was added, the solution turned a
brown/pink color.
Analyze and Conclude
6. The solution was clear but turned milky
white as a solid precipitate formed.
1. Pb(NO3)2 Na2CO3 → 2NaNO3
PbCO3
2. Silver nitrate reacts with sodium sulfide
to form sodium nitrate and silver
sulfide.
3. 2AgNO3 Na2S → 2NaNO3 Ag2S
4. The solution is clear at the start but a
solid black precipitate forms when Na2S
is added.
Mixture
Initial Temperature T1 (°C)
Final Temperature T2 (°C)
NaCl(s) + H2O (l)
25.00
24.90
NaNO3(s) + H2O (l)
25.00
24.00
NaCH3COO(s) + H2O (l)
25.00
25.96
Analyze and Conclude
3. NaCl
1. NaCl: 0.10; NaNO3: 1.00;
NaCH3COO: 0.96
4. heat NaNO3(s) → Na+(aq) NO3–(aq)
NaCH3COO(s) → Na+(aq)
2. Endothermic: NaNO3; NaCl
Exothermic: NaCH3COO
CH3COO–(aq) heat
158 Answer Key
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Lab 15—Using Energy to Observe Chemical Changes
sx07CAGr8_VPhyLab_Answer.fm Page 159 Friday, September 7, 2007 7:00 AM
Lab 16—Boiling Point Elevation
5. Amount of water, kind of solid
dissolved.
Table 1
Mass of NaCl
2.9399 g
Boiling temperature
of pure water
99.47°C
Boiling temperature
of solution
100°C
Mass of NaCl
3.9994 g
Change in boiling
temperature
+0.53°C
Boiling temperature
of pure water
99.47°C
Boiling temperature
of solution
100.21°C
Change in boiling
temperature
+0.74°C
Analyze and Conclude
1. The boiling temperature was higher.
Mass of NaCl; Temperature
Table 2
2. 100°C 99.47°C 0.53°C
3. To raise its boiling point, coolant is
dissolved in the water that cools the
engine. With the addition of the coolant,
the water in the radiator remains a
liquid over a larger temperature range.
4. The boiling point would increase.
9. When the mass of dissolved NaCl was
increased, the amount of elevation of
the boiling point increased. This is
because the more ions of NaCl there are,
the greater the interference with the
normal evaporation and boiling of the
water molecules.
Lab 17—Endothermic vs Exothermic
Data Table
T1
T2
DT (T2-T1)
Exothermic or
Endothermic?
NaCl (s) + H2O (l)
25
24.75
0.25
Slightly
Endothermic
NaNO3 (s) + H2O (l)
25
24
1
Endothermic
NaCH3COO (s)+ H2O (l)
25
26
1
Exothermic
NaOH (s) + H2O (l)
25
30
5
Exothermic
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Mixture
10. Answers will vary. NaCl
lowers the temperature of
the solution, so it wouldn't
freeze until the temperature
was lower.
11. Answers will vary. Cold packs for
injuries, chemical handwarmers, some
glowsticks get warm after you snap
them.
Answer Key
159
sx07CAGr8_VPhyLab_Answer.fm Page 160 Friday, September 7, 2007 7:00 AM
Lab 18—Acid-Base Reactions
Analyze and Conclude
1. Yellow
Blue
2. 25.00 cm3 of NaOH
3. The pH changed rapidly from low pH to
high pH.
All the acid was consumed, so the
additional base caused the pH to change
quickly. The indicator must change its
color when the pH changes.
4. HCl(aq) NaOH(aq) ➔ H2O(l)
NaCl(aq)
5. The presence of hydrogen ions (H+)
The presence of hydroxide ions (OH–);
They have combined to form water
molecules; Hydrogen ions combine with
hydroxide ions to form neutral water.
6. NaCl
7. The graph shows that the pH rises very
slightly until 25.00 cm3 of base have
been added. Then the curve rises
sharply and quickly levels off near
pH 12.
8. pH 7
Lab 19—Energy of a Chemical Reaction
Analyze and Conclude
1. 25.00°C
28.3°C; 35 seconds
2. Approximately 3.375°C
4. If the temperature decreased, the
reaction must be endothermic. The
reaction would have drawn heat from
the surrounding water and caused the
water temperature to go down.
3. The reaction is exothermic because the
temperature increased as heat was
given off by the chemical reaction.
Lab 20—Investigating the Properties of Alpha and Beta Particles
3. A spot in the center of the phosphor
screen
4. The spot moves right.
5. The spot moves left.
7. Another spot
8. The spot moves to the left. It is opposite.
Electrons move right when applying a
160 Answer Key
magnetic field and alpha particles
move left.
9. The spot moved to the right. Again, it is
opposite. Electrons move left in the
electric field and alpha particles move
right.; The alpha particle is massive
compared with the electron. It is more
than 7000 times heavier!
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2. Electron Gun; Negative; Phosphor
Screen
sx07CAGr8_VPhyLab_Answer.fm Page 161 Friday, September 7, 2007 7:00 AM
Lab 21—Measuring Speed
Procedure
2. The ball that rolls across the table in a
short time is going faster than the ball
that takes a long time. The speed of the
first ball is greater than the speed of the
second.
Table 1: Answers will vary.
Analyze and Conclude
1. The graph shows a straight line starting
from the point (0 s, 0 cm) and ending at
the point corresponding to the time and
distance at which the ball reached the
end of the table. The line slopes upward
from left to right.
2. All lines start from the point (0 s, 0 cm)
and slope upward and to the right at
different angles. Each line ends at the
point corresponding to the time and
distance at which that ball reached the
end of the table.
3. The steeper the slope, the faster the ball
moved.
It would be even steeper than any of the
lines on the graph.
It would be less steep than any of the
lines on the graph.
4. Table 2: Answers will vary.
5. Divide the distance between the two
cities by the time it took to travel
between them.
Lab 22—Graphing Motion
Analyze and Conclude
1. Graphs will vary depending on the
masses used.
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2. Each point on the three lines shows the
distance a ball traveled in the
corresponding time.
3. They each have a different steepness
(slope). The balls traveled at different
speeds. Each reached the end of the
table at different times.
4. The slopes tell the different speeds of
the three balls. The ball with the least
mass is the fastest and the most massive
ball is the slowest.
5. The dog starts at position zero. In
4 seconds the dog travels 20 meters.
The dog remains in one place for
4 seconds, and then travels 40 meters
in 2 seconds.
6. The slope of the line from 0 seconds to
4 seconds is not as steep as the slope
from 8 seconds to 10 seconds. That
means that the dog must have moved
more slowly at the beginning of the
10 seconds than at the end.
Answer Key
161
sx07CAGr8_VPhyLab_Answer.fm Page 162 Friday, September 7, 2007 7:00 AM
Lab 23—Acceleration
2. As the ball rises, it will slow down. As
the ball falls, it will speed up.
4. The ball accelerates all along its path. As
the ball rises, it slows down, so it
experiences negative acceleration or
deceleration. At the peak of the
trajectory, the ball’s direction changes,
so it is accelerating. As the ball falls it
speeds up, so it is accelerating.
Analyze and Conclude
4. A negative slope above the x-axis
indicates the ball is slowing down. A
negative slope below the x-axis
indicates the ball is speeding up.
5. The plunger force affects how fast the
ball is moving, but the acceleration is
always the same either going up or
coming down. The slope of the falling
and rising is the same value. The
acceleration is not affected by the force
of the plunger.
1. Graphs will vary.
3. The velocity versus time graphs are not
horizontal lines. They have slopes. The
slope of a velocity versus time graph is a
measure of the acceleration.
Lab 24—Forces
3. The ball still fell even though the rocket
was on, but it fell more slowly.
4. The object is to find the force that will
make the net force zero. Then the forces
are balanced. This occurs when the ball
doesn’t go down or up.
Table 1: Data will vary; Table 2: Data will
vary.
Analyze and Conclude
1. The forces in Table 2 were used in
different directions. Sometimes the
forces were balanced and sometimes
they pushed the ball off at other angles.
2. The ball does not move.
3. The ball speeds up or changes direction.
4. The builders should understand that
they need a net force stronger than the
forces opposing the rocket’s motion.
2. 9.8 N
A metal sled would be easier to push
because metal has a smoother surface. It
would not stick or grip the cement as
much.
Table: Results will vary.
Analyze and Conclude
1. Friction between the sled and the table
2. Plastic on plastic was the best
combination for sliding. Plastic is the
smoothest of the available materials
162 Answer Key
and produced the least friction. Rubber
on rubber produced the most friction.
The sled barely moved when the
plunger hit the sled.
3. It would take more force to move
the sled.
4. The larger the friction, the stronger the
force must be to move the object.
5. Somewhere in between—the tire should
be smooth so it can roll, but with
enough stickiness to grip the road.
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Lab 25—Measuring Friction
sx07CAGr8_VPhyLab_Answer.fm Page 163 Friday, September 7, 2007 7:00 AM
Lab 26—Acceleration and Friction
Analyze and Conclude
3. The shape of the line is not as curved
and is less steep. As the friction becomes
greater, the sled cannot accelerate as
well.
4. The shapes of the curves become less
steep faster.
5. Friction causes the sled to slow down.
The more friction there is, the faster the
sled slows down. The rocket force
causes the sled to speed up.
Lab 27—Gravity and Free Fall Motion
Analyze and Conclude
1. Individual graphs will vary.
2. Answers will vary. The graphs without
air resistance are the same. The graphs
with air resistance show that the small
ball accelerates more slowly than the
same ball without air resistance. The
large ball with air resistance accelerates
much more slowly and even stops
accelerating.
3. Without air resistance, the balls are in free
fall. Their mass and radius do not affect
how fast they fall. Every object falls with
the same constant acceleration when
only the force of gravity is acting on it.
4. As the balls begin to fall, they have
almost constant acceleration, just as if
they were in free fall. But as the balls
speed up, air resistance increases and
they can’t accelerate as much. At some
point, the force of air resistance becomes
equal to the force of gravity and the ball
stops accelerating.
5. When an object falls with air resistance,
there will always be a time when the
force of air resistance balances the force
of gravity. This balancing point marks
the end or termination of acceleration
and the beginning of constant velocity
for the remainder of the fall.
6. The balls would speed up much faster
so the increasing air resistance would
cause them to hit terminal velocity
faster.
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Lab 28—Newton’s First Law
1. Graphs will vary.
Analyze and Conclude
2. The lightest mass was easiest. The most
massive ball was hardest. The more
mass an object has, the greater its
inertia.
3. Because there is no friction, the rocket
force is the only force working to change
the motion or inertia of the ball. Any
force will be enough to stop the ball
eventually.
4. Any type of force could change the
motion of the ball: friction, air
resistance, or gravity.
5. The ball would keep moving at constant
velocity forever. It doesn’t matter what
the mass is.
The greater the mass of an object, the
greater its inertia is.
Answer Key
163
sx07CAGr8_VPhyLab_Answer.fm Page 164 Friday, September 7, 2007 7:00 AM
Lab 29—Newton’s Second Law
The velocity versus time graphs show
that the velocity is increasing linearly.
The ball with the smallest mass and the
greatest force had the greatest
acceleration.
2. They will have some sort of slope. The
velocity will be changing over time.
Analyze and Conclude
1., 2. Graphs will vary.
3. The position versus time graphs are
curved because as the ball travels
farther, it moves faster.
4. Use a ball with a very small mass.
5. You can decrease the mass or increase
the force, or both.
Lab 30—Newton’s Third Law
2. Newton’s third law says that two
colliding objects exert equal and
opposite forces on each other. A force,
exerted on a small mass, results in a
large acceleration or velocity. The same
force exerted on a large mass cannot
accelerate it very much, so it moves
slowly.
2. The heavy ball will hit the lighter ball
just as hard as the light ball hits back.
The light ball will bounce back going
faster and the heavy ball will bounce
back going slower.
Analyze and Conclude
1. When the masses were the same, the
velocities of each ball after the collision
were the same. When one ball was more
massive than the other, the light ball
moved with large velocity and the
heavy ball barely moved.
3. Answers will vary depending on the
prediction.
4. Because the forces act on different
objects
Mass
(kg)
Velocity
Before
Velocity
After
Reaction
Ball 1
10
–10
10
goes to the right
Ball 2
10
10
–10
goes to the left
Ball 1
20
–10
3.333
goes slower to the right
Ball 2
10
10
–16.667
goes faster to the left
Ball 1
50
–10
–9.216
goes slower to the left
Ball 2
1
10
–29.216
goes faster to the left
Ball 1
1
–10
29.216
goes faster to the right
Ball 2
50
10
9.216
goes slower to the right
Trial 2
Trial 3
Trial 4
164 Answer Key
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Trial 1
sx07CAGr8_VPhyLab_Answer.fm Page 165 Friday, September 7, 2007 3:32 PM
Lab 31—Conservation of Momentum
Analyze and Conclude
1. Yes, because the total momentum before
the collision equaled the total
momentum after.
2. Yes, they would obey the law. Answers
may vary for the second part of this
question.
3. It could have a large velocity.
4. Answers will vary but should include
the product of mass and velocity and
the measure of motion.
Trial 1
Mass
(kg)
Velocity
Before
(m/s)
Velocity
After
(m/s)
Momentum
Before (mass x
velocitybefore)
Momentum
After (mass x
velocityafter)
Ball 1
10
–10
10
–100
100
Ball 2
10
10
–10
100
–100
0
0
Total Momentum =
Trial 2
Mass
(kg)
Velocity
Before
(m/s)
Velocity
After
(m/s)
Momentum
Before (mass x
velocity before)
Momentum
After (mass x
velocity after)
Ball 1
15
–10
–2
–150
–30
Ball 2
10
0
–12
0
–120
–150
–150
Total Momentum =
Lab 32—Floating Objects
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Table 1 (Sample Data)
Table 2 (Sample Data)
Volume Virtual Fluid (mL)
226.2
Mass of beaker only (g)
101.30
Mass of beaker and
Virtual Fluid (g)
607.1
Volume of Virtual Fluid
only (mL)
226.2
Volume of Virtual Fluid
and steel (mL)
247.5
Mass of steel ball (g)
162.1
Analyze and Conclude
1. 505.8 g; Subtract the mass of the beaker
from the mass of the beaker and the
Virtual Fluid.
2. 2.24 g/mL
3. 247.5 mL 226.2 mL 21.3 mL
m d V; The mass of the Virtual Fluid
is m (2.24 g/mL)(21.3 mL) 47.7 g.
4. 47.7 g 0.477 kg;
0.477 kg 9.8 m/s2 0.467 N
5. The buoyant force acting on the steel
ball is equal to the weight of the
displaced fluid and is 0.467 N.
6. The force of gravity acting on the steel
ball is its mass in kg multiplied by
9.8 m/s2 or
0.1621 kg 9.8 m/s2 1.59 N.
7. The force of gravity pulling down on the
steel ball is much larger than the buoyant
force pushing up on the steel ball, so the
ball sinks.
Answer Key
165
sx07CAGr8_VPhyLab_Answer.fm Page 166 Friday, September 7, 2007 3:37 PM
Lab 33—Density and Buoyancy
5. Subtract the volume of the Virtual Fluid
from the volume of both the Virtual
Fluid and the plastic sample.
Table 1 (Sample Data)
Mass of
Sample
(g)
Volume of
Virtual Fluid
(mL)
Volume of
Virtual Fluid
and Sample
(mL)
Volume of
Sample
(mL)
Density
(g/mL)
Plastic
18.355
228
246
18
1.02
Ice
17.071
229
248
19
0.898
Aluminum
46.698
227.5
245
17.5
2.67
Pine Wood
9.302
229
243.5
14.5
0.64
Sample
10. Subtract the mass of the empty beaker
from the mass of the beaker and the
ethanol.
Table 2 (Sample Data)
Mass of
Empty
Beaker (g)
Mass of
Beaker and
Sample (g)
Mass of
Sample (g)
Volume of
Sample (mL)
Density
(g/mL)
Ethanol
101.309
230.992
129.683
227
0.57
Water
101.309
327.856
226.547
226
1.00
Olive Oil
101.309
306.665
205.356
229
0.897
Mercury
101.309
3195.596
3094.287
227.5
13.60
Sample
Analyze and Conclude
3. Density, not weight, determines
whether or not an object will float or
sink in a fluid. An object that is denser
than the fluid it is in will sink. An object
that is less dense than the fluid will
float.
4. The density of the olive oil is
0.897 g/mL. Only the pine wood has a
lower density (0.64 g/mL), so only the
wood will float.
166 Answer Key
6. The density of olive oil is 0.90 g/mL.
The density of water is 1.00 g/mL. Olive
oil would float on water.
7. From top to bottom: ethanol, pine wood,
olive oil, ice, water, plastic, aluminum,
mercury. Density determines where the
items are placed from lowest density on
top to highest density on bottom.
© Pearson Education, Inc. All rights reserved.
1., 2. See tables.
5. The density of mercury is 13.6 g/mL.
None of the solids have a higher density
and none will sink.
sx07CAGr8_VPhyLab_Answer.fm Page 167 Friday, September 7, 2007 7:00 AM
Lab 34—The Work of the Egyptians
3.
Weight of sled =
490N
4.
Minimum Pushing Force
Time to reach top
491N
1min 26 sec
5. The length of the ramp must change.
6. Answers will vary.
Data Table 1
Ramp Angle
Ramp Length (m)
Force (N)
90°
50
491
60°
57.74
425
45°
70.71
347
30°
100
246
10°
287.94
86
Ramp Angle
Force (N)
Ramp Length (m)
Work (J)
90°
491
50
24550
60°
425
57.74
24539.5
45°
347
70.71
24536.37
30°
246
100
24600
10°
86
287.94
24762.84
7. Answers will vary.
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Data Table 2
Answer Key
167
sx07CAGr8_VPhyLab_Answer.fm Page 168 Friday, September 7, 2007 7:00 AM
Analyze and Conclude
8. The length of the ramp will have to
increase if the angle decreases and you
need to still reach the same height.
9. The steeper the angle, the greater the
force required.
11. Since the Egyptians were limited in the
amount of force they could get from
manpower, it would be best to use the
steepest ramp that would allow them
to push the blocks up, so they wouldn’t
have to push for very long.
10. The amount of work required was the
same. It was not dependent on the
length of the ramp.
Lab 35—Falling Elevator
4. Answers will vary.
Data Table 1
Mass (kg)
Height
(number of floors)
Height (meters)
Force (N)
Time (s)
3000
20
80
30000
28
3000
20
80
40000
6
3000
20
80
29500
77
3000
20
80
35000
29
3000
20
80
42000
10
Answers will vary. It should take half as much force.
5. Answers will vary.
Data Table 2
Height
(number of floors)
Force (N)
Time (s)
1500
20
20000
6
1500
20
15000
28
1500
20
14800
51
1500
20
14750
77
1500
20
14700
80
168 Answer Key
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Mass (kg)
sx07CAGr8_VPhyLab_Answer.fm Page 169 Friday, September 7, 2007 7:00 AM
6. Answers will vary.
WORK
Force (N)
Distance (m)
Work (J)
Full Elevator
29500
80
2360000
Half Full
14750
80
1180000
POWER
Work (J)
Time (s)
Power (watts)
Full Elevator
2360000
77
30649
Half Full
1180000
77
15324
Analyze and Conclude
elevator. It doesn’t reduce the amount of
force you have to pull with at all. It
would be best to use a pulley system.
7. The elevator that was most full. It took
more force to move it.
8. They reduce the amount of input force
thus reducing the amount of work and
power required.
10. For safety reasons, buildings are
limited to the space and size of motor
allotted to the elevators. This restricts
the load an elevator can carry safely.
9. A single fixed pulley requires the same
amount of input force as the output
force, which is just the weight of the
Lab 36—Thermal Energy
3. Answers will vary.
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Data Table 1: Energy Level 1
Ball Number
Mass (kg)
Velocity (m/s)
Kinetic
Energy (J)
1
10
2.274
25.85538
2
20
2.372
56.26384
3
10
1.061
5.628605
4
15
3.036
69.12972
5
5
2.247
12.62252
6
1
1.5
1.125
7
100
1.7
144.5
8
200
2.062
425.1844
9
7
1.5
7.875
10
1000
1.965
1930.613
Total Kinetic
Energy
2678.797
They will speed up, have more kinetic energy, which also means greater thermal energy.
Answer Key
169
sx07CAGr8_VPhyLab_Answer.fm Page 170 Friday, September 7, 2007 7:00 AM
4. Answers will vary.
Data Table 2: Energy Level 2
Ball Number
Mass (kg)
Velocity (m/s)
Kinetic
Energy (J)
1
10
10
500
2
20
5.049
25.92401
3
10
9.194
422.64818
4
15
3.949
116.9595075
5
5
20.34
1034.289
6
1
4.69
10.99805
7
100
1.708
145.8632
8
200
2.235
499.5225
9
7
8.589
258.1902235
10
1000
1.673
1399.4645
Total Kinetic Energy
4642.867171
5. Answers will vary.
Table 3: Energy Level 3
Mass (kg)
Velocity (m/s)
Kinetic
Energy (J)
1
10
6.531
213.269805
2
20
4.306
185.41636
3
10
8.817
388.697445
4
15
3.691
102.1761075
5
5
7.468
139.42756
6
1
9.177
42.1086645
7
100
4.236
897.1848
8
200
1.493
222.9049
9
7
12.759
569.7722835
10
1000
1.805
1629.0125
Total Kinetic Energy
170 Answer Key
4389.970426
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Ball Number
sx07CAGr8_VPhyLab_Answer.fm Page 171 Friday, September 7, 2007 7:00 AM
because it has the most amount of
kinetic energy, which is what helps
produce heat.
Analyze and Conclude
8. The one with the greatest amount of
energy, the last run.
11. It shows how molecules have smaller
parts, which help to carry the energy of
that system. This simply shows how
the tiny atoms work inside a molecule.
9. As you add energy to the system, the
kinetic energy increases.
10. The highest energy level would be the
best to heat up another molecule
Lab 37—Potential Energy to Kinetic Energy
to friction or thermal energy. All of the
mechanical energy in the beginning was
stored in gravitational energy and since
the velocity at the beginning was zero,
the kinetic energy at the beginning was
zero also.
3. Answers will vary. The sled has the
same amount of energy everywhere on
the ramp.
8. Because the ramp is frictionless, all
gravitational potential energy is
converted to kinetic energy and not lost
Height of the
Sled (Y) (m)
Speed at the
bottom (Vtot) (m/s)
Initial Potential
Energy (J)
Final Kinetic
Energy (J)
52.84
69296.29
69801.64
141.421
Data Table 2
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Initial:
Height of the
Sled (Y) (m)
Speed (Vtot) (m/s)
Potential Energy (J)
Kinetic Energy (J)
141.421
0.00
69296.29
0
0.00
52.84
0.00
69801.64
Middle:
Bottom:
Data Table 3
Ramp Angle
Height of the Sled
(Y) (m)
Speed at the bottom
(Vtot) (m/s)
Kinetic Energy
(J)
45°
141.421
52.84
69801.64
60°
141.069
53.063
70392.05
15°
141.686
52.867
69872.99
Your choice: ___
Answer Key
171
sx07CAGr8_VPhyLab_Answer.fm Page 172 Friday, September 7, 2007 7:00 AM
energy was conserved, when kinetic
increased, potential decreased.
Analyze and Conclude
14. The energy didn’t change.
16. Energy is lost to friction and thermal
energy.
15. The kinetic energy increased as the
sled sped up down the ramp. The total
Lab 38—Temperature and Volume of a Gas
2. As the temperature is increased, the
volume will increase.
Analyze and Conclude
1. The graph is a straight line that slopes
upward from the lower left to the upper
right.
Temperature (°C)
Volume (cm3)
100
1531
200
1941
300
2352
2. Yes, the graph shows that as the
temperature increases, the volume also
increases.
400
2762
3. linear
500
3172
600
3583
700
3993
4. If the temperature were decreased, the
volume would also decrease because
volume and temperature vary directly.
Lab 39—Specific Heat
Data Table
Al
Au
Stainless Steel
7.3547
51.0616
23.3374
volume of water (mL)
100
100
100
mass of water (g)
99.8
99.8
99.8
initial temperature of water (°C)
25.00
25.00
25.00
initial temperature of metal (°C)
200.00
200.00
200.00
max temp of water + metal (°C)
27.38
27.39
29.21
Specific Heat (J/g°C)
0.783
0.113
0.441
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mass of metal (g)
Analyze and Conclude
Answers will vary. DTwater 5 27.38°C 2 25°C 5 2.38°C
Answers will vary. q = 99.8g 3 2.38°C 3 4.184 J/(°C?g) 5 993.8 J
Answers will vary. DTaluminum 5 200°C 2 27.38°C 5 172.62°C
Answers will vary. CAl = 993.8 J/(7.3547 g)(172.62°C) 5 0.783 J/°C?g
Answers will vary. CAu = 997.98 J/(51.0616 g)(172.61°C) 5 0.113 J/°C?g
Answers will vary. CSteel = 1757.94 J/(23.3374 g)( 170.79°C) 5 0.441 J/°C?g
Answers will vary. The gold can will absorb the heat in the room faster and your
drink will heat up faster than in the aluminum can.
16. Answers will vary. The steel would heat up faster than the aluminum, but that could
lead to hot spots. Once the aluminum heated up, it would keep the heat longer than
the steel pot would.
9.
10.
11.
12.
13.
14.
15.
Answer Key
172
sx07CAGr8_VPhyLab_Answer.fm Page 173 Friday, September 7, 2007 7:00 AM
Lab 40—Blackbody Radiation
3. Data Table
Temperature (K)
Wavelength (nm)
3000
950
3100
922
3200
880
3300
853
3400
839
3500
826
3600
798
4. The intensity increases as the
temperature increases. The maximum
shifts left as the temperature increases.
5. The peak intensity does not move far
enough to occur in the visible region
and is always in the infrared region.
The fact that the peak intensity does not
occur in the visible range does not mean
that there is no visible light radiated.
The curve shows significant intensity of
light in the visible region, just not the
peak intensity.
6. As the temperature increases, the peak
height increases. You would think that
we would get more and more light from
light bulbs as they heat up.
7. Answers will vary. Repeated heating
close to the melting point wears out the
filament.
Lab 41—Wave Properties of Light
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2. The laser because it provides light at a
single wavelength.
500 nm
3.0 mm.
3. No.
As the slit spacing increases, the
number of lines in the diffraction
pattern increases.
4. There won’t be an interference pattern if
the spacing between the slits is smaller
than the size of the wavelength. When
the slits are farther apart, you will start
to see more and more diffraction bands
as the waves interfere more
5. Answers will vary.
6. Color changes from green to red. The
number of lines also changes.
7. The pattern is the same after allowing
enough photons to diffract.
It cannot diffract. What you see as the
diffraction pattern that builds up over
time is really the statistics of where each
individual photon will hit the screen.
It is uncertain what each individual
photon will do, but the properties of a
large collection of photons can be easily
predicted.
8. Light behaves like a particle, and the
wave—nature of light is really a
representation of the statistics or
uncertainty exhibited in an experiment.
Answer Key
173
sx07CAGr8_VPhyLab_Answer.fm Page 174 Friday, September 7, 2007 7:00 AM
Lab 42—Particle Properties of Light
2. The laser emits coherent light, which is
the same wavelength and in phase.
1 nW
400 nm
Na, sodium metal foil
The phosphor screen detects electrons,
and it glows momentarily at the
positions where the electrons impact the
screen. The laser light is causing the
ejection of electrons from the surface of
the sodium metal.
The signal is not as intense and flickers
as each photon impacts the phosphor
screen.
3. The signal is more intense than at
1 photon/second, but the same as at
1 nW.
4. The signal disappears. 450 nm.
Wavelength
(nm)
Energy
Light color
400
most
Dark blue
600
least
Orange
450
middle
Light blue
6. Wavelength corresponds to the energy
of light emitted but intensity is the
amount of light.
7. Violet light has a shorter wavelength,
but more energy than orange light.
Violet light has enough energy to eject
electrons but orange light does not.
Lab 43—Atomic Emission Spectra
2. Orange 590nm
6. There are a lot more peaks in the Blue
and Purple range.
Data Table
Color of Light (highest peaks in visible range)
Sodium (Na)
Yellow
Mercury (Hg)
Blue
Neon (Ne)
Red
Hydrogen (H2)
Blue-Green and Red
Helium (He)
Blue and Yellow
8. Answers will vary.
Lab 44—Plane Mirror Images
3. Answers will vary. The object will look
like it is farther and farther away. It will
get smaller and smaller.
5. The image size did not change.
9. The image is flipped. The color order on
the ball is reversed with every mirror.
The object looks reversed.
174 Answer Key
10. The image seems as if it is located
inside the mirror.
11. Answers will vary.
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Gas
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Lab 45—Concave Mirror Images
3. Answers will vary. The object will look
like it is farther and farther away. It will
get smaller and smaller.
7. The image be upside down and the
Height Factor is greater than 1. The
image is reversed.
4. The image is right side up and larger
than the actual object. The image is
flipped.
8. The image is still reversed; it is still
upside down but smaller. The Height
Factor can be less than 1.
6. It is ahead of the focal point. It is a
virtual image. Height Factor: 2.278
9. The image disappears. You can’t see any
image at all.
Lab 46—Convex Mirror Images
3. Answers will vary. The image will get
bigger.
6. The image looked bigger. It is still right
side up.
7. The image gets bigger. It is still not as
big as the original object.
8. The objects reflected in the convex
mirror are smaller than we are used to
seeing in plane mirrors, so we would
think they would be farther away than
they actually are.
9. Answers will vary.
Lab 47—Looking at Images
3. Answers will vary. The image will
change to a virtual image on the same
side as the object.
Data Table
Distance of
object from
lens (cm)
Distance of
image from
lens (in.)
Inverted
(yes/no)
26
12
yes
smaller
0.375
20
14
yes
smaller
0.625
16
16
yes
same size
1.0
12
24
yes
larger
2.0
6
24
no
larger
4.0
Height
Factor
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175 Answer Key
Image bigger
or smaller
than object?
sx07CAGr8_VPhyLab_Answer.fm Page 176 Friday, September 7, 2007 7:00 AM
5. No image.
Analyze and Conclude
6. The focal point is where the image
transitions between being real or virtual
and switches which side of the lens it is
on.
7. The image looks smaller and the image
is inverted.
8. The image becomes virtual and not
inverted.
9. You could take an object and move it
until you find the place where it flips
from inverted image to a virtual noninverted image.
Lab 48—Ohm’s Law
Data Table 1
Resistance
Voltage (V)
Current (A)
1
1.5
1.50
10
1.5
0.150
100
1.5
0.015
1000
1.5
0.001
10000
1.5
0.0
Data Table 2
Resistance
Voltage (V)
Current (A)
100
1.5
0.015
100
3
0.030
100
4.5
0.045
100
9
0.90
100
12
0.120
Analyze and Conclude
8. It means the current cannot flow as fast
or as much. If increased too much then
the current would not go at all.
9. The current increased proportionally.
10. The circuit is like a river because it has
a current, which follows paths. The
voltage source would be like water that
flows over a waterfall, which makes
the water flow fast and have a lot of
176 Answer Key
11. Yes it does. When you have a fraction if
you increase the numerator then the
number will get bigger, if you increase
the denominator the number will get
smaller. This is exactly what happened
from our data as in answers 7 and 9.
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7. The current decreased proportionally.
energy. The resistor would be like a
dam, or something constricting the
flow, and the current is like the water
that flows through the obstacles and
over the waterfalls.
sx07CAGr8_VPhyLab_Answer.fm Page 177 Friday, September 7, 2007 7:00 AM
Lab 49—Circuit Diagrams
voltage source, or battery, to the other
end. If something isn’t connected, then
the current won’t flow.
4. Answers will vary.
5. Descriptions will vary.
Analyze and Conclude
6. The circuit diagrams are neater and
simpler, and it is easier to follow the
current and see if everything is
connected.
7. Current flows through the wires in a
complete loop from one side of the
8. When you are building something
electrical, and you need to see where the
wires need to go.
9. Answers may vary. Some may include
legos, rule books, game manuals,
connect the dots.
Lab 50—Building Electrical Circuits
Data Table 1: Series Circuit
Phases
Lights?
Brightness
One Light Bulb
Yes
Bright
Two Light Bulbs
Yes
Dimmer
Three Light Bulbs
Yes
Even Dimmer
Data Table 2: Parallel Circuit
Resistor Number
Lights?
Brightness
Two Light Bulbs
Yes
Bright
Three Light Bulbs
Yes
Bright
Analyze and Conclude
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5. The brightness was the same through
all the light bulbs. The brightness
decreased with more bulbs.
6. The brightness was the same through
all the bulbs; the brightness wasn’t
changed with more bulbs.
7. You would be able to design the circuit
to achieve the appropriate outcome. If
you need to be able to turn off one of
the elements but have everything else
work, you should use parallel. If you
need everything to turn off when one
thing is taken out, then use series.
8. I would plug them in and then break
one of the bulbs, or take one out so the
circuit is not complete see what
happens to the rest. If some lights go
out then I know that some are in series,
if some stay on then I know that some
are in parallel.
9. Some Christmas tree lights and fuses
are in series. Home outlets are in
parallel.
10. Answers will vary. The bulb in series
gets brighter when there are more
bulbs in parallel in front of it in the
series. The bulbs in parallel have lower
resistance, so the second bulb can burn
brighter. Putting more bulbs in parallel
drops the effective resistance even
more, as if it were a tiny little light
bulb, so that is why the second bulb
can glow brighter.
Answer Key
177
sx07CAGr8_VPhyLab_Answer.fm Page 178 Friday, September 7, 2007 7:00 AM
Lab 51—Making Observations of Our Solar System
orbit is also elliptical. The comet moves
much faster when it is closer to Earth
than when it is farther away.
4. The outside planets move more slowly
than the inner planets. The orbits of the
planets seem almost circular. Pluto’s
orbit is elliptical or oval. The comet’s
Time Display at the End of
One Orbit (year:day)
Period of One Orbit (in
Earth years)
Mercury
2006:88
0.24
Venus
2006:223
0.61
Earth
2007:0
1.00
Mars
2007:321
1.88
Jupiter
2017:319
11.87
Saturn
2035:157
29.43
Uranus
2089:362
83.99
Neptune
2170:286
164.78
Pluto
2253:338
247.93
Comet
2081:169
75.46
Object
5. Answers will vary. The orbits of the
comet and the planets aren’t in the same
plane (they are tilted with respect to
each other), so there are only two points
where they could intersect potentially,
and it isn’t very probable that the comet
and the planet would be exactly in that
point of their orbit at the same time.
6. Answers will vary. See answer above for
correct response.
7. Jupiter and Saturn have the most
moons. Venus and Mercury don’t have
any moons.
8. Answers will vary.
Lab 52—Tracking the Phases of the Moon
Analyze and Conclude
1. The light of the sun can illuminate only
the side of the moon that faces it. As the
moon orbits Earth, observers on Earth
can see only the side of the Moon that
faces Earth. That side may not be totally
lit up. It depends on where the moon is
in its orbit.
2. Answers will vary depending on the
prediction.
178 Answer Key
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3. The light of the sun can illuminate only
the side of the moon that faces it. As the
moon orbits Earth, observers on Earth
can see only the side of the moon that
faces Earth. Depending on where the
moon is in its orbit, the side of the moon
that faces Earth may not be totally lit up.
sx07CAGr8_VPhyLab_Answer.fm Page 179 Friday, September 7, 2007 7:00 AM
Lab 53—Measuring the Orbital Speed of the Planets
2. Answers will vary.
Analyze and Conclude
1. Answers in the table may vary.
Earth’s acceleration is actually quite
small, so you can’t feel it.
2. Yes, it is very fast.
3. Although Earth is moving very fast, a
person cannot feel motion, just change
in motion, or acceleration. The value of
4. The sun is pulling Earth toward it with
such a strong gravitational force that the
planet can’t escape even traveling at the
calculated velocity.
Lab 54—How Strong is Gravity?
Analyze and Conclude
1. Graphs will vary.
2. The speed of falling is higher on some
planets (Jupiter, Neptune) and lower on
others (all other planets).
Answers will vary depending on the
planets chosen.
3. The speed is changing at a constant rate.
This means that acceleration is constant
and that there is a constant gravitational
force.
4. Answers will vary.
5. Answers will vary.
Lab 55—Why Pluto is Not a Planet
Table 1: Observation Table
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Planetary
Object
Mass
(kg)
Inclination Average Orbital
(degrees)
Radius (km) Object Radius (km)
Mercury
3.3022 1023
7
5.65 107
2.44 103
Venus
4.8685 1024
3.39
1.08 108
6.05 103
Earth
5.9742 1024
0
1.50 108
6.37 103
Mars
6.4185 1023
1.85
2.26 108
3.40 103
Jupiter
1.8986 1027
1.3
7.80 108
7.15 104
Saturn
5.6846 1026
2.49
1.43 109
6.03 104
Uranus
8.6832 1025
0.77
2.86 109
2.56 104
Neptune
1.0243 1026
1.77
4.50 109
2.48 104
Pluto
1.314 1022
17.15
5.28 109
1.20 103
Answer Key
179
sx07CAGr8_VPhyLab_Answer.fm Page 180 Friday, September 7, 2007 7:00 AM
Table 2: Orbital Radius
Object
Location 1
(km)
Location 2
(km)
Location 3
(km)
Location 4
(km)
Mercury
70155536
53805238
46259656
55687123
Venus
107938764
107208975
107926361
108653710
Earth
149650141
147182927
149828247
152178996
Mars
206612261
225794000
249225198
224193989
Jupiter
777383685
740765896
784393231
818390820
Saturn
1515085008
1428374172
1352415642
1431906595
Uranus
2733964553
2856727592
3002680357
2827555376
Neptune
4444438326
4495131842
4545769675
4498655572
Pluto
5160382426
4094273632
5079892983
6787210330
7.
Object Radius
Smallest
--------
--------
--------
Medium
Pluto
Mercury
Mars
Venus
Earth
-------
--------
Uranus Neptune
---------
Largest
Saturn
Jupiter
---------
Largest
Saturn
Jupiter
Mass
Smallest
--------
--------
--------
Medium
Pluto
Mercury
Mars
Venus
Earth
-------
--------
Uranus Neptune
Inclination
--------
--------
--------
Medium
-------
--------
---------
Largest
Earth
Uranus
Jupiter
Neptune
Mars
Saturn
Venus
Mercury
Pluto
8. Pluto has a much larger orbital radius.
9. Answers will vary.
10. The planets have moons that seem to
orbit around the planet in the plane of
the planets orbit; however, the moon of
Charon orbits perpendicular to the
orbital direction. The size of Charon is
180 Answer Key
close to the size of Pluto, where many
of the other planets’ moons are not
close in size at all.
11. Answer will vary.
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Smallest