Download essential unit 10 (e10)

AP PHYSICS 1
(SECONDARY)
ESSENTIAL UNIT 10 (E10)
(Electric Charge, Field/Current/Resistance)
(Giancoli Chapter 16 and Chapter 18-1 to 18-4)
(July 2015)
Unit Statement: The introduction to electricity in this unit covers conductors and insulators,
and Coulomb’s Law which relates the force between two electrical point charges as function of
their distance apart. The ideas of electrical fields and the motion of electrical charges (currents)
is also briefly discussed. By the end of the unit, students should be able to relate underlying
electrostatic concepts to real world application. (Estimated class time three weeks)
Essential Outcomes: (must be assessed for mastery)
1. The Student Will define electric current and circuit.
2. TSW apply the concepts that electric charge is conserved and the net charge of a system
is equal to the sum of the charges of all the objects in the system (EK 1.B.1)
3. TSW construct an explanation of the two-charge model of electric charge based on
evidence produced through scientific practices. (LO 1.B.2.1)
4. TSW will make claims that the smallest observed unit of charge that can be isolated is
the electron charge, also known as the elementary charge. (EK 1.B.3)
5. TSW connect the concepts of gravitational force and electric force to compare
similarities and differences between the forces. (LO 3.C.2.2)
6. TSW use Coulomb’s law qualitatively and quantitatively to make predictions about the
interaction between two electric point charges (interactions between collections of
electric point charges are not covered in Physics 1 and instead are restricted to
Physics 2). (LO 3.C.2.1)
7. TSW recognize resistivity of a material depends on its molecular and atomic structure
and temperature of the material.
8. TSW interpret a graph of the energy changes within an electrical circuit with only a
single battery and resistors in series and/or in, at most, one parallel branch as an
application of the conservation of energy (Kirchhoff’s loop rule) (LO 5.B.9.1)
9. TSW apply conservation of energy concepts that demonstrate the validity of Kirchhoff’s
loop rule (∑∆V = 0) in a circuit with only a battery and resistors either in series or
in, at most, one pair of parallel branches. (LO 5.B.9.1)
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10. TSW apply conservation of energy (Kirchhoff’s loop rule) in calculations involving the
total electric potential difference for complete circuit loops with only a single
battery and resistors in series and/or in, at most, one parallel branch. (LO 5.B.9.1)
11. TSW describe Kirchhoff ’s junction rule as the conservation of electric charge in
electrical circuits.
12. TSW use a description or schematic diagram of an electrical circuit to calculate unknown
values of current in various segments or branches of the circuit.
Guided or Essential Questions:
1. How can the charge model be used to explain electric phenomena?
2. How can the forces between two charges be characterized using Newton’s third law?
3. How can preexisting knowledge of forces and energy be applied to processes involving
electrically charged objects?
4. What is lightning, and why is it so dangerous?
5. What are the fundamental carriers of electrical charge, and how may they be used to
charge objects?
6. How is gravitational force similar to electrical force, and in what ways are these forces
very different?
7. How are voltage, current, and resistance related in a series circuit?
8. How are voltage, current, and resistance related in a simple parallel circuit?
9. What makes charges move?
10. How do electric circuits demonstrate the conservation of electric charge?
Key Concepts:
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Static Electricity (amber effect)
Law of Conversation of Electric Charge
Conductors
Semiconductors
Electrometers
Quantized
Point Charge
Electrostatic force (Coulomb’s Force)
Test charge
Electric Field lines
Gravitation Field
Electric Flux
Electric Cell
Electrolyte
Circuit
Open Circuit
Complete Circuit
Ohm’s Law
Resistors
Kirchhoff’s Junction rule
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Electric Charge
Ions
Polar
Nonconductors (insulators)
Electroscope
Coulomb’s Law
Permittivity of free space
Electrostatics
Electric Field
Superposition Principle
Electric Dipoles
Gauss’s Law
Battery
Electrodes
Terminal
Electric Current
Ampere
Conventional Current
Resistance
Resistivity
Some Common Equations for this Unit:
F
Coulomb’s law
kq1q 2
r2
Electric field strength
F kq

q0 r 2
q
EA 
0
q

E

 0A  0
V
E
s
q
I
t
E
Gauss’s law for a point charge
Parallel plate capacitor
Electric field strength, volts/meter
Definition of electrical current
V  IR
R
Voltage
Resistance
L
A
Schedule of suggested laboratory experiments (guided inquiry format is suggested for labs
shaded in gray)
Lab #
47
48
49
Name of Laboratory
Instructional Activity: Static
Electricity Investigation
Instructional Activity:
Brightness Investigation
Voltage and Current
Description of Lab
Students follow the directions of the two online activities
to gain experience with electrostatic phenomena while
building understanding of electric charges and their
interactions in conductors and insulators. Students use
sticky tape and a variety of objects to make qualitative
observations of the interactions when objects are
charged, discharged, and recharged.
Web; see links below
Students working with a partner use wires, light bulbs,
and batteries in guided-inquiry tasks that introduce the
concepts of electric circuits, series connections, and
parallel connections. The tasks require students to make
predictions about the brightness of light bulbs in a circuit
when some of the bulbs are removed.
To determine the relationship between the current
through a resistor and the voltage across the resistor.
Giancoli
Associated Science
Practices
1.2, 3.1, 4.1, 4.2,
5.1, 6.2, 7.2
1.2, 3.1, 4.1, 4.2,
4.3, 5.3, 6.1, 6.4, 7.2
1.1, 1.2, 1.4, 1.5,
2.1, 2.2, 3.1, 4.1,
4.2, 4.3, 5.1, 5.3,
6.1, 6.4, 7.2
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50
Resistance and Resistivity
To investigate the effects of cross-sectional area and
length on the flow of current through a roll of Play-Doh.
Giancoli
51
Coulomb’s Law
1.4, 2.1, 2.2, 3.1,
4.1, 4.2, 4.3, 5.1,5.3,
6.1, 6.4, 7.2
To estimate the charge on two identical, equally charged
spherical pith balls of known mass.
1.1, 1.2, 1.4, 1.5,
Giancoli
4.2, 4.3, 5.1, 5.3,
2.1, 2.2, 3.1, 4.1,
6.1, 6.4, 7.2
52
Series and Parallel Circuits
To investigate the behavior of resistors in series, parallel,
and series-parallel circuits. The lab should include
measurements of voltage and current.
1.1, 1.2, 1.4, 1.5,
2.1, 2.2, 3.1, 4.1,
4.2, 4.3, 5.1, 5.2,
Giancoli
5.3, 6.1, 6.4, 7.2
Suggested Materials:
1. Giancoli, D.C. Physics: Principles with Applications. Englewood Cliffs, NJ: Pearson
Education.
2. Appel, K, Ballen, C, Gastineau, J, Vernier, D. Physics with Vernier. Beaverton, OR;
Vernier Software and Technology, 2010.
3. Puri, O; Zober, P. Physics. A laboratory manual; Boston, Mass. N.Y: Pearson Custom
Pub., 2002. 8th edition
Suggested Technology Resources:
Labs, in class activities, quizzes, videos and demos:
1. Balloons and Static-PhET Simulations- Why does a balloon stick to your sweater? Rub a
balloon on a sweater, then let go of the balloon and it flies over and sticks to the sweater.
View the charges in the sweater, balloons, and the wall. http://phet.colorado.edu/en/simulation/balloons
2. Battery and Voltage- PhET Simulation- Look inside a battery to see how it works. Select
the battery voltage and little stick figures move charges from one end of the battery to the
other. A voltmeter tells you the resulting battery voltagehttp://phet.colorado.edu/en/simulation/battery-voltage
3. Circuit Construction Kit- PhET Simulation- An electronics kit in your computer! Build
circuits with resistors, light bulbs, batteries, and switches. Take measurements with the
realistic ammeter and voltmeter. View the circuit as a schematic diagram, or switch to a
life-like view. - http://phet.colorado.edu/en/simulation/circuit-construction-kit-dc
4. Electric Field PhET Simulation - http://phet.colorado.edu/en/simulation/efield
5. Travoltage- PhET Simulation- Make sparks fly with John Travoltage. Wiggle Johnnie's
foot and he picks up charges from the carpet. Bring his hand close to the door knob and
get rid of the excess charge. http://phet.colorado.edu/en/simulation/travoltage
6. Charges and Sticky Tape- Seat Activity.
http://physicsed.buffalostate.edu/SeatExpts/EandM/charges/index.htm
7. Straws and Pens- Seat Activity- Using such everyday items as a straw, tape, plastic pen
and various types of cloth, we'll explore static electricity and how items can be charged,
discharged, and recharged.
http://physicsed.buffalostate.edu/SeatExpts/EandM/straws/index.htm
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8. Charge and Fields- PhET Simulation- Move point charges around on the playing field
and then view the electric field, voltages, equipotential lines, and more. It's colorful, it's
dynamic, it's free. http://phet.colorado.edu/en/simulation/charges-and-fields
9. Journey through Franklin’s Electrical Revolution. Interactive online activity.
http://www.pbs.org/benfranklin/shocking/index.html
10. Benjamin Franklin videos on electricity. http://www.history.com/topics/americanrevolution/benjamin-franklin/videos/ben-franklin-sparks-electricity#ben-franklin-sparkselectricity
11. This applet shows a simple circuit containing one resistor. In addition there is a voltmeter
(parallel to the resistor) and an ammeter (in series with the resistor). http://www.walterfendt.de/ph14e/ohmslaw.htm
12. Online notes on Multi-loop Circuits and Kirchoff's Ruleshttp://physics.bu.edu/~duffy/py106/Kirchoff.html
13. More online notes- http://www.allaboutcircuits.com/vol_1/chpt_2/3.html
14. Applet for a simplified version of Millikan's oildrop experiment.
http://www.physics.rutgers.edu/~jgoett/millikan/millikan.html
Note- All links to online resources were verified before publication. In cases where links are no longer
RUBRIC FOUND ON FOLLOWING PAGE…………………………….
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SUGGESTED RUBRIC AP PHYSICS 1 E10
Student Name: __________________________
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Date: _______________________
To receive a ‘B’, the student must show ‘B’ level mastery on all essential outcomes (TSW’s).
The teacher’s discretion on the student’s holistic performance on the unit, including such items as: the above ‘A’ level rubric, the unit project, group work and class
discussions will determine ‘A’ level mastery.
If grading for AP test preparation, please refer to Course Outcome Rubric.
The Student Will
1. TSW define electric current and circuit.
2. TSW apply the concepts that electric charge is
conserved and the net charge of a system is equal to the
sum of the charges of all the objects in the system (EK
1.B.1)
3. TSW construct an explanation of the two-charge model
of electric charge based on evidence produced through
scientific practices. (LO 1.B.2.1)
4. TSW will make claims that the smallest observed unit
of charge that can be isolated is the electron charge,
also known as the elementary charge. (EK 1.B.3)
5. TSW connect the concepts of gravitational force and
electric force to compare similarities and differences
between the forces. (LO 3.C.2.2)
6. TSW use Coulomb’s law qualitatively and
quantitatively to make predictions about the interaction
between two electric point charges (interactions
between collections of electric point charges are not
covered in Physics 1 and instead are restricted to
Physics 2). (LO 3.C.2.1)
7. TSW recognize resistivity of a material depends on its
molecular and atomic structure and temperature of the
material.
‘A’* LEVEL
Makes predictions, using the conservation of electric
charge, about the sign and relative quantity of net
charge of objects or systems after various charging
processes, including conservation of charge in simple
circuits. (LO 1.B.1.2)
Approach chosen is clearly shown, clearly written &
all elements are valid.
Valid approach with minor errors that don’t disrupt
understanding.
Challenges the claim that an electric charge smaller
than the elementary charge has been isolated. (LO
1.B.3.1)
Approach chosen is clearly shown, clearly written &
all elements are valid.
Makes the claim that an electric charge smaller than the
elementary charge has been isolated. (LO 1.B.3.1)
Appropriate concepts and equations are used and
fully understood.
Appropriate concepts and equations are used and are
mostly understood but employed with errors.
Justifies the selection of data needed to determine
resistivity for a given material.
Chooses the selection of data needed to determine
resistivity for a given material.
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‘B’ LEVEL
Defines electric current and circuits as:
a. An electrical current is a movement of
charge through a conductor.
b. A circuit is a closed loop of electrical
current.
Makes claims about natural phenomena based on
conservation of electric charge. (LO 1.B.1.1)
Valid approach with minor errors that don’t disrupt
understanding.
Comments
8. TSW interpret a graph of the energy changes
within an electrical circuit with only a single
battery and resistors in series and/or in, at most,
one parallel branch as an application of the
conservation of energy (Kirchhoff’s loop rule)
(LO 5.B.9.1)
9. TSW apply conservation of energy concepts that
demonstrate the validity of Kirchhoff’s loop rule
(∑∆V = 0) in a circuit with only a battery and
resistors either in series or in, at most, one pair
of parallel branches. (LO 5.B.9.1)
10. TSW apply conservation of energy
(Kirchhoff’s loop rule) in calculations involving
the total electric potential difference for
complete circuit loops with only a single battery
and resistors in series and/or in, at most, one
parallel branch. (LO 5.B.9.1)
11. TSW describe Kirchhoff ’s junction rule as the
conservation of electric charge in electrical
circuits.
Constructs a graph of the energy changes within an
electrical circuit with only a single battery and
resistors in series and/or in, at most, one parallel
branch as an application of the conservation of energy
(Kirchhoff’s loop rule).
Approach chosen is clearly shown, clearly written
& all elements are valid.
Uses conservation of energy concepts to design an
experiment that will demonstrate the validity of
Kirchhoff’s loop rule (∑∆V = 0) in a circuit with only
a battery and resistors either in series or in, at most,
one pair of parallel branches.
Appropriate concepts and equations are used and fully
understood.
Approach chosen is clearly shown, clearly written
& all elements are valid.
Designs an investigation of an electrical circuit with
one or more resistors in which evidence of
conservation of electric charge can be collected and
analyzed.
Applies conservation of electric charge
(Kirchhoff’s junction rule) to the comparison of
electric current in various segments of an
electrical circuit with a single battery and resistors
in series and in, at most, one parallel branch and
predict how those values would change if
configurations of the circuit are changed.
Appropriate concepts and equations are used and
fully understood.
12. TSW use a description or schematic diagram
of an electrical circuit to calculate unknown
values of current in various segments or
branches of the circuit.
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Appropriate concepts and equations are used and
are mostly understood but employed with errors.