Download Lesson 1

th
8
Science
Lesson 1 –
Circuit of Inquiries –
A Preassessment
Inquiry 1.1
The Single Pulley
• Procedure
– Materials:
– 1.
– 2.
– 3……
• Inquiry 1.1
Inquiry 1.1
Conclusion
A pulley changes the direction of a
force.
Inquiry 1.2
The Pegboard Lever
• Procedure
– Materials
– 1.
– 2.
– 3. …..
• Inquiry 1.2
• Inquiry 1.2
•Conclusion
• As washers are added, they are placed
closer to the pivot point. Fewer
washers are placed farther from the
pivot point.
Inquiry 1.3
The Hand Warmer
• Procedure
– Materials
– 1.
– 2.
– 3……
• Inquiry 1.3
• Inquiry 1.3
•Conclusion
• Temperature increased due to friction.
Inquiry 1.4
Constructing a Graph
• Procedure
– Materials:
– 1.
– 2.
– 3……
• Inquiry 1.4
• Inquiry 1.4
•Conclusion
• The ball slowed down over time.
Inquiry 1.5
Transforming Energy
• Procedure
– Materials:
– 1.
– 2.
– 3……
• Inquiry 1.5
• Inquiry 1.5
• Conclusion
• The hand’s kinetic energy (motion) converted to
electrical energy. The electrical energy
becomes heat and light in the bulb.
Inquiry 1.6
The Puck Launcher
• Procedure
– Materials
– 1.
– 2.
– 3…….
• Inquiry 1.6
• Inquiry 1.6
•Conclusion
• The farther back the puck is pulled,
the longer the time it takes for it to
stop. Friction stops the puck.
Inquiry 1.7
Up the Incline
• Procedure
– Materials
– 1.
– 2.
– 3……
• Inquiry 1.7
• Inquiry 1.7
•Conclusion
• It requires a stronger force to pick up the
mass. It requires less force to pull the
mass up the incline but it is moved across
a greater distance.
Inquiry 1.8
Down the Ramp
• Procedure
– Materials
– 1.
– 2.
– 3……
• Inquiry 1.8
• Inquiry 1.8
•Conclusion
• Gravity is the force that
accelerates the car down the
incline. Friction stops the car.
Vocabulary – Lesson 1
1. Galileo Galilei -- born in Pisa, Italy – 1564;
• Recorded observations – shared imaginative
and creative mind;
• Inventor (telescope) – discovered four moons
of Jupiter;
• Astronomer;
• Believed earth revolved around the Sun –
controversial idea to leaders of the Church –
put on trial for heresy – kept under house
arrest for the rest of this life.
Lesson 2
Lesson 2
• Can I make a battery?
• How can I make a battery using the
materials given?
• Can I make a battery that will work?
• How do you make a battery?
L2
• Lesson 2
• If _________________,then __________
because _________________.
• Lesson 2
•
•
•
•
Materials
1.
2.
3.
• Lesson 2
• Lesson 2
• Lesson 2
• THREE MAIN COMPONENTS OF A
BATTERY
• Negative terminal – (zinc) – accumulates
negative charge (gains electrons).
• Positive terminal – (copper) – accumulates
positive charge (loses electrons).
• Electrolyte – a liquid solution or a paste
whose molecules spontaneously separate
into positively or negatively charged atoms
or groups of atoms, called ions.
L2
Oxidation-Reduction Reaction
The battery is assembled by putting a copper and zinc strip
in a container filled with a copper sulfate solution
(electrolyte). A chemical process called oxidationreduction reaction occurs. In this reaction, the zinc
electrode easily accumulates electrons; the copper
electrode loses electrons. The gain or loss of electrons
at an electrode is the result of chemical reactions
between the electrodes and the electrolyte. This
accumulation of opposite charges on the electrodes
produces the electric potential of the battery. The
battery’s electric potential – how much electrical energy
per charge the chemical reaction generates – is
measured in volts.
L2
How the Battery Works
Chemical reactions at the electrodes create a current when
the assembly is placed in the copper sulfate solution. At
the zinc electrode, a reaction occurs in which zinc atoms
lose two electrons each to the zinc strip and are
converted into positively charged zinc ions that go into
the solution. This conversion of metallic zinc into
aqueous zinc ions gradually eats away the zinc
electrode. At the copper electrode, the positive copper
ions in the copper sulfate solution gain two electrons
each at the copper electrode, thereby becoming neutral
metallic copper that accumulates on the electrode. This
movement of ions in the electrolyte creates a current in
the battery.
L2
The wires that connect the light bulb to the
battery provide a path for electrons
released by the zinc to flow to the copper
electrode. This movement of electrons
creates a current in the wires and
completes the circuit. As the current flows
through the light bulb, the electrical energy
associated with the electrons is
transformed into light and heat in the bulb.
L2
VOCABULARY – LESSON 2
• In this lesson, we made a device
composed of two metal electrodes in an
electrolyte that transfers chemical energy
into electrical energy. This device is
known as a
(2) battery.
L2
VOCABULARY – LESSON 2
• “Something is happening” when the bulb
lights. This is evidence that the battery is
a source of energy for the bulb.
• This ability to do work is:
(3) energy.
L2
VOCABULARY – LESSON 2
• The battery is made of two metal strips, copper and zinc.
• The zinc strip is negatively charged because it gains
electrons.
• The copper strip is positively charged because it loses
electrons.
• The strips are
(4) electrodes.
• Negatively-charged particles of an atom are
(5) electrons.
L2
VOCABULARY – LESSON 2
• The liquid solution in the battery is an
(6) electrolyte.
• A battery with a liquid electrolyte is a
(7) wet-cell battery.
• A battery with an electrolyte made of paste is a
(8) dry-cell battery.
L2
VOCABULARY – LESSON 2
•
The light eventually stopped burning after being removed from the copper
sulfate solution. The chemical reaction could only generate a certain
amount of electrical energy per charge. This is the
(9) electric potential of the battery.
•
The electric potential of the battery is measured in
(10) volts.
•
This is named after the person who built the first electric battery (11) Alessandro Volta.
•
A device made of two metal electrodes in an electrolyte that transfers
chemical energy into electrical energy is a
(12) battery.
L2
Lesson 3
Lesson 3
• Which uses the most energy, a light bulb
or an electric motor?
• Does a bulb or a motor use the most
energy?
• Is there a difference in the amount of
energy needed by a battery and a motor?
• Do different devices use different amounts
of energy?
L3
• Lesson 3
• If _________________,then __________
because _________________.
• Lesson 3
•
•
•
•
Materials
1.
2.
3.
• Lesson 3
Light bulb v. motor
3 minute charging time
Lit time of bulb v. running time of motor
Light bulb
Motor
• Lesson 3
• Current flowing in the circuit carries
energy. As the current flows through
the bulb, the chemical energy stored
in the battery becomes light and heat
energy in the bulb. When all the
battery’s available chemical energy
has been converted to other forms of
energy, the battery is “dead.”
L3
• When a battery is charging, energy is
being put into it. The charger runs a
current “backward” through the battery,
reversing the chemical processes and
converting electrical energy to chemical
energy, which is stored in the battery. The
current is said to go backward because
the flow of ions in the electrolyte is
opposite to the flow when the battery is
discharging and supplying electrical
energy to a circuit.
L3
• The battery stores chemical energy –
potential energy that is later transformed
to electric potential energy. The charging
process converts electrical energy to
chemical energy. The chemical energy is
later converted back to electrical energy,
and then to light and heat in the bulb.
L3
• The cycle of charging and discharging
batteries cannot continue indefinitely
because of gases that escape from the
cell and because of impurities in the cells.
Eventually, rechargeable batteries must be
replaced.
L3
Vocabulary – Lesson 3
•
Energy stored in the battery is
(13) chemical energy.
•
The device in a car that generates an electric current when an
engine runs and sends a current through a battery to charge it
and keep it from running down is an
(14) alternator.
•
•
The electrodes in a car battery are also called
(15) terminals.
•
How much energy a battery will store and generate is the
(16) capacity of a battery.
Lesson 4
Lesson 4
QUESTION – LESSON 4
• How does charging time of battery affect lit
time of bulb?
• How does charging time affect the stored
energy in a rechargeable battery?
• Lesson 4
• If _________________,then __________
because _________________.
• Lesson 4
•
•
•
•
Materials
1.
2.
3.
• Lesson 4
Charging Time v. Lit Time
Grp
1
30
60
120
240
480
L4
Class Average: Time
Flashlight Stays On (s)
Time Flashlight Stays On (s)
Time Batteries are
Charged (s)
Grp
2
Grp
3
Grp
4
Grp
5
Grp
6
• Lesson 4
• Lesson 4
Vocabulary – Lesson 4
•
The stored chemical energy is the battery is
changed to electrical energy and light and heat
in the bulb. These changes are energy
(17) transformations.
•
The amount of energy stored in a rechargeable
battery is directly related to the amount of time
the battery is charged. This relationship is
(18) proportional.
L4
Vocabulary – Lesson 4
• Mechanical energy may be converted to
electrical energy. The device that does
this is a
(19) generator.
Vocabulary – Lesson 4
•
A practical way to analyze data is to construct and
interpret a graph.
• The data being controlled is the
(20) independent variable.
• The independent variable is plotted on the
(21) x-axis.
• The x-axis runs across or
(22) horizontally.
L4
Vocabulary – Lesson 4
• The data that depends on the independent variable is
(23) dependent variable.
• The dependent variable is plotted on the
(24) y-axis.
• The y-axis runs up and down or
(25) vertically.
L4
Vocabulary – Lesson 4
• The intersection of the two axes on a
graph is the
(26) origin.
• A line that goes through the middle of
plotted data points on a graph is a
(27) best fit line.
Lesson 5
Lesson 5
Question – Lesson 5
• What is the relationship between force,
mass, and weight?
• How is force and the stretch of a rubber
band related?
• How do you measure elastic force?
• Lesson 5
• If _________________,then __________
because _________________.
• Lesson 5
•
•
•
•
Materials
1.
2.
3.
• Lesson 5
Elastic Force Created by
Stretching a Rubber Band
Stretching Distance
(cm.)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
Elastic Force (N)
• Lesson 5
• Lesson 5
L5
Mass v. Weight
WEIGHT is a measure of the force of
gravity pulling on a body.
MASS is a measure of how much matter is
in a body.
L5
Weight v. Mass
Mass (number of
washers)
1
2
3
4
5
6
L5
L
Weight (N)
• Lesson 5
L5
Vocabulary – Lesson 5
•
A push or a pull on an object is a
(28) force.
•
A tool used to measure force is a
(29) spring scale.
•
Before being used, a spring scale must be set or
(30) calibrated.
•
One type of force measured by a spring scale is
(31) gravitational force.
L5
Vocabulary – Lesson 5
•
The metric unit of force is the
(32) newton (N).
(We use the British system – ex. – pound (lb.),
ounce (oz.), ton.
• 1 N = 1/5 lb.
•
The international basis for scientific measurement is
(33) metric units.
L5
Vocabulary – Lesson 5
• The measure of the force of gravity on an object is
(34) weight.
• The metric unit for measuring weight is the newton (N).
• The amount of matter (“stuff”) in an object is
(35) mass.
• Mass is measured with a
(36) balance.
• The common metric units for measuring mass is the
(37) gram, kilogram.
L5
Vocabulary – Lesson 5
• The earliest and best known person for having studied the nature of
gravitational force is
(38) Isaac Newton.
• The force of attraction between two bodies is
(39) gravitational force.
• It is directly proportional to the mass of an object – the
greater the mass, the greater the gravitational force between
two objects.
• It also depends on the distance between objects.
– The gravitational force between two objects is inversely proportional to the square
of the distance between the objects – if the distance between two bodies doubles,
the gravitational force between them will be one-fourth as much. This is the
(40) law of universal gravitation.
L5
Vocabulary – Lesson 5
• When the rubber band was pulled, it pulled
back. For every action there is an equal
and opposite reaction. This is
(41) Newton’s third law of motion.
Vocabulary – Lesson 5
• When something stretches when acted on by a force, it
has the properties of
(42) elastic force.
• The person to first describe the nature of elastic force
was
(43) Robert Hooke.
• Force is directly proportional to the stretch of a spring is
(44) Hooke’s Law.
Lesson 6
Lesson 6-1
Question – Lesson 6.1
• Does friction depend on the type of surfaces in
contact?
• Do different surfaces produce different amounts
of friction?
• What factors affect the force of friction on
different surfaces?
• How is pulling force related to the force of
friction?
• Lesson 6-1
• If _________________,then __________
because _________________.
• Lesson 6-1
•
•
•
•
Materials
1.
2.
3.
• Lesson 6-1
Force Needed to Move a Block
.27 m (27 cm.) Over Different Surfaces
Sliding Surface
Tabletop
Waxed Paper
Paper Towel
Fine Sandpaper
Coarse Sandpaper
L 6-1
Force
(N)
Trial 1
Trial 2 Trial 3
Trial 4
Average
• Lesson 6
L 6-1
• Lesson 6-1
Lesson 6-2
Question – Lesson 6.2
• Does changing the load change the force
of friction across a surface?
• If you add a larger load, will the force of
friction change?
• Lesson 6-2
• If _________________,then __________
because _________________.
• Lesson 6-2
•
•
•
•
Materials
1.
2.
3.
• Lesson 6-2
Force Needed to Move Two and Three Blocks
0.27 m (27 cm.) Over Different Surfaces
Sliding
Surface
Tabletop
Waxed
Paper
Paper
Towel
Fine
Sandpaper
Coarse
Sandpaper
L 6-2
Force
(N)
AVG. Two
Two
Two
AVG. Three Three Three AVG.
One blocks blocks blocks Two blocks blocks blocks Three
block Trial
Trial
Trial blocks Trial
Trial
Trial blocks
1
2
3
1
2
3
• Lesson 6-2
L 6-2
• Lesson 6-2
Lesson 6-3
Question 6.3
• Does changing the surface areas in
contact change the amount of friction?
• Does surface area affect friction?
• How is surface area and friction related?
• Lesson 6-3
• If _________________,then __________
because _________________.
• Lesson 6-3
•
•
•
•
Materials
1.
2.
3.
• Lesson 6-3
Changing the Surface Area
AREA
TABLETOP
COARSE
FINE
SANDPAPER SANDPAPER
WAXED
PAPER
PAPER
TOWEL
1 2 3 AV 1 2 3 AV 1 2 3 AV 1 2 3 AV 1 2 3 AV
Trial
FLAT
END
SIDE
L 6-3
Changing the Surface Area
(summary)
AREA
FLAT
END
SIDE
6-3
TABLETOP
COARSE
FINE
SANDPAPER SANDPAPER
WAXED
PAPER
PAPER
TOWEL
• Lesson 6-3
Vocabulary – Lesson 6
•
The force that resists motion between two surfaces in
contact with each other is
(45) friction.
•
When two objects are in contact and are rubbing
against each other, they are producing
(46) sliding friction.
•
The size of the force is the
(47) magnitude.
L6
Vocabulary – Lesson 6
•
The force of friction does not change when the base
area of an object in contact with a surface changes.
The area in contact is called the
(48) surface area.
•
When the surface area changes, the force per unit
area changes. This is known as changes in
(49) pressure.
L6
Vocabulary – Lesson 6
• The result of forces between the stationary block and the
surface area is
(50) static friction.
• It takes a certain amount of force to overcome
static friction and start the block moving (until the
bonds between the block and the surface area are
broken).
• The force needed to put the block in motion is
greater than the force needed to keep the block
moving.
L6
Vocabulary – Lesson 6
• An object at rest will remain at rest and an object in motion will move
at constant speed in a straight line if no unbalanced forces act on it.
This is known as
(51) Newton’s First Law of Motion (law of
inertia).
• For every action there is an equal and opposite reaction. This is
known as
(52) Newton’s Third Law of Motion.
• The speed at which an object is traveling in a single direction is
• (53) velocity.
L6
Lesson 7
Lesson 7
Question – Lesson 7
• What are the conditions that produce the
maximum force from a motor?
• What arrangement of string and batteries
will allow the motor to produce the most
force?
• Lesson 7
• If _________________,then __________
because _________________.
• Lesson 7
•
•
•
•
Materials
1.
2.
3.
• Lesson 7
Diameter v. Number of
Washers Lifted (Force)
DIAMETER
Plastic pulley (large
diameter)
Nail (small diameter)
L7
NUMBER OF WASHERS LIFTED
( one battery)
Arrangement and Number of Batteries
v. Number of Washers Lifted (Force)
Number of
Batteries
Number of washers lifted
Parallel
Series
Arrangement
Arrangement
1
2
3
Maximum force exerted by the motor: ______________________
L7
• Lesson 7
Vocabulary – Lesson 7
•
A device that converts electrical energy to
mechanical energy is a
(54) motor.
•
The motor exerted the most force when the
string wound around the nail rather than the
plastic pulley. This was because the plastic
pulley was thicker than the nail. The thickness
or width of an object is the
(55) diameter.
L7
Vocabulary – Lesson 7
• When batteries are arranged with terminals connected
from positive to negative to positive…, the arrangement
is known as a
(56) series connection.
•
•
•
•
•
•
All electrons flow through a single path.
Voltages combine.
More current is produced.
Energy is more rapidly delivered to the motor.
It makes the motor more powerful.
If one battery discharges, the circuit does not work.
Vocabulary – Lesson 7
• When batteries are arranged with terminals connected
from positive to positive or from negative to negative…,
the arrangement is called a
(57) parallel connection.
•
•
•
•
•
•
There is more than one path for electrons to travel.
Voltage is the same as a single battery.
There is a small amount of current.
Energy is transformed at a slower rate.
Each battery lasts longer.
If one battery runs down, the others continue to supply energy.
Vocabulary – Lesson 7
• Several energy transformations take place in this lesson.
• Energy is stored in the bonds between atoms. This energy is
known as
(58) chemical energy.
• Chemical energy is transformed to energy that causes electrons to
move. This is a transformation to
(59) electrical energy.
• The flow of electrons is
(60) electricity.
• Electrical energy is transformed into energy that runs the motor.
This energy in moving objects is
(61) mechanical energy.
L7
Lesson 8
Work
• Work – when a force acts on an object and
it moves some distance.
WORK = Force (N) x Distance (m)
L8
WORK
Alice pulls a sled with a force of
12 N. She pulls the sled
through a distance of 5 m.
How much work does Alice do
on the sled?
L8
WORK
Work = force x distance
Work = 12 N x 5 m = 60 N-m
L8
WORK
Michael lifts his book bag, which
weighs 25 N, from the floor to a
desktop that is 0.80 m above the
floor. How much work does
Michael do on the bag?
L8
WORK
Work = Force x Distance
25 N x 0.80 m = 20.0 N-m
L8
Inquiry 8.1
Calculating the Work Done
on Different Surfaces
SURFACE
TABLETOP
WAXED
PAPER
PAPER
TOWEL
FINE
SANDPAPER
COARSE
SANDPAPER
L8
EFFORT
FORCE (N)
EFFORT
DISTANCE (m)
WORK DONE
(N-m)
• 1. What force are you
working against when you
lift a backpack?
•
L 8.1b
• 2. In which of the following cases
is work, as defined by scientists,
being done?
• A. Someone tries to move a
piano, but the piano won’t budge.
•
L 8.1b
• B. A tow truck is pulling a
car slowly along the street.
•
L8.1b
• C. A student is studying for
a mathematics exam.
L 8-1b
• D. A student is pushing
a grocery cart around a
store.
•
L 8.1b
• E. Another student is
standing in line holding a
12-N bag of potatoes.
•
L 8.1b
• F. A student pushes against
the school building.
•
L 8.1b
Lesson 8
Question – Lesson 8
• How do you calculate work?
• What is the relationship between force applied
and the work that is done?
• How much work is required to lift a load?
• How do you measure the work to lift a load?
• Lesson 8
• If _________________,then __________
because _________________.
• Lesson 8
•
•
•
•
Materials
1.
2.
3.
• Lesson 8
Lifting a Load
• 1. Motor force with three batteries in
series: _________________
• 2. Work done by a motor when it lifts a
load 10.0 cm. (0.10 m)
• Work = _______ x _______ = ______
L 8-2
3. Weight of six washers:______________
4. Work to raise six washers:
Work = ______ x _______ = _______
5. Your estimate of sled’s weight: _______
6. Sled’s actual weight: _________
L 8-2
7. Work to lift sled 10.0 cm. (0.10 m):
Work = _________ x ______ = _______
L 8-2
• Lesson 8
Vocabulary – Lesson 8
•
What happens when an object changes its position by moving in
the direction of the force that is being applied is
(62) work.
• Work = force x distance (w = fd)
• Work involves a force applied across a distance.
•
The metric unit of work is the
(63) newton-meter (N-m).
•
A newton-meter is also a
(64) joule (J).
•
James Joule – described the relationship between work and energy.
L8
Vocabulary – Lesson 8
• A force is applied to lift the sled. This is
the
(65) effort force.
• The distance the sled moves is the
(66) effort distance.
Vocabulary – Lesson 8
• Electric current flows through the wire. The unit
used to describe how much electric current flows
through a wire is the
(67) ampere (amp).
• Andre Ampere
• The electric potential of a battery is measured in
(68) volts.
• Alessandra Volta
Lesson 9
POWER
POWER is the rate of doing work, or the
amount of work done each second.
POWER = WORK = (N-m)
TIME
s
The common unit of power is the watt (W).
1 watt = 1 newton-meter
second
L9
POWER
A girl pushes on a box at a steady
pace with a force of 8.0 N. She
moves the box 3.0 m in 5.0 s.
What is her power output?
L9
POWER
Power = work = Newton-meter = watts
time
second
8.0 N x 3.0 m
L9
Lesson 9
Question – Lesson 9
• How do you calculate the power of a
motor?
• Lesson 9
• If _________________,then __________
because _________________.
• Lesson 9
•
•
•
•
Materials
1.
2.
3.
• Lesson 9
Number of Batteries
and Time to Lift the Load
NUMBER
OF
BATTERIES
1
2
3
L9
TIME 1
(s)
TIME 2
(s)
TIME 3
(s)
AVG. TIME
(s)
• Lesson 9
Number of Batteries
and Power of the Motor
Number
of
Batteries
1
2
3
L9
Force
(N)
Distance
(m)
WORK
(N-m)
TIME
(s)
POWER
(W)
• Lesson 9
• Lesson 9
Vocabulary – Lesson 9
• The rate at which work is done is
(69) power.
• work divided by time
• measure of the rate at which energy transformations take
place
• The unit used to measure power is the
(70) watt (w).
• 1 w = 1 joule per second
• James Watt
L9
Lesson 10
Lesson 11
Lesson 11
Question – Lesson 11
• What purpose does an inclined plane serve?
• How does an inclined plane affect work?
• What is an inclined plane?
• How is an inclined plane used?
• For what is an inclined plane used?
L11
• Lesson 11
• If _________________,then __________
because _________________.
• Lesson 11
•
•
•
•
Materials
1.
2.
3.
• Lesson 11
Work and the Inclined Plane
Hole
Number
6
8
12
16
20
L 11
Rise
(cm)
Run
(cm)
Slope
Effort
Force
(N)
Effort
Distance
(m)
Work
(N-m)
• Lesson 11
• Lesson 11
Vocabulary – Lesson 11
• The force applied to move an object, like the cart, across
a distance is
(71) effort force.
• The distance an object moves to reach a certain point is
(72) effort distance.
• The force needed to lift a load straight up is the
(73) load force.
Vocabulary – Lesson 11
• The vertical distance an object is lifted is
(74) load distance.
• The angle of an incline is the
(75) slope.
• A type of simple machine that increases effort
distance and reduces effort force is an
(76) inclined plane.
Lesson 12
Lesson 12
Question – Lesson 12
• What is the purpose of a pulley?
• How does a pulley affect the amount of
work done on an object?
• Lesson 12
• If _________________,then __________
because _________________.
• Lesson 12
•
•
•
•
Materials
1.
2.
3.
• Lesson 12
Effort Force, Effort Distance, and Work
in Pulley Systems
Type of
Pulley
System
Single fixed
Single fixed,
single
movable
Double
fixed, single
movable
Double
fixed, double
movable
L 12
Effort Force
(N)
Effort
Distance
(m)
Calculations
Work
(N-m)
• Lesson 12
Vocabulary – Lesson 12
• A simple machine that changes the
magnitude and/or direction of the effort
force required to do work is a
(77) pulley.
Lesson 13
• T
Lesson 13
Inquiry 13.1
Left side
# of
washers
Right side
# of holes from
fulcrum
# of
washers
# of holes from
fulcrum
Question – Lesson 13
• How does a lever affect work?
• How does a lever work?
• What is the purpose of a lever?
• Lesson 13
• If _________________,then __________
because _________________.
• Lesson 13
•
•
•
•
Materials
1.
2.
3.
• Lesson 13
• Lesson 13
Vocabulary – Lesson 13
• The fixed pivot point of a lever is the
(78) fulcrum.
• A type of simple machine that uses a small
force to lift a large load is a
(79) lever.
Lesson 14
Vocabulary – Lesson 14
• The factor by which a machine multiples the effort force is
(80) mechanical advantage.
• The ratio of effort distance to load distance when a machine does
work is
(81) ideal mechanical advantage.
• The ratio of load force to effort force needed to lift or move a load is
(82) actual mechanical advantage.
ACTUAL MECHANICAL ADVANTAGE IS LESS THAN IDEAL
MECHANICAL ADVANTAGE BECAUSE OF FRICTION.
Lesson 15
Vocabulary – Lesson 15
• How much work that is put into a machine
by its user is
(83) work input.
• The work done by a machine against the
resistance is
(84) work output.
Lesson 16
Lesson 17
Lesson 18
• T
Lesson 18
Question – Lesson 18
• How does the speed of a fan car change
at .4 m intervals across a distance of 2
meters?
• Lesson 18
• If _________________,then __________
because _________________.
• Lesson 18
•
•
•
•
Materials
1.
2.
3.
• Lesson 18
Time and Distance Data for the Fan Car
Distance Position
Interval
(m)
Time
(s)
Trial 1
1
0.0 - 0.4
2
0.4 – 0.8
3
0.8 – 1.2
4
1.2 – 1.6
5
L 18
1.6 – 2.0
Trial 2
Trial 3
Avg.
Speed
(m/s)
Average
• Lesson 18
Vocabulary – Lesson 18
• The rate at which an object changes its position over
time is
(85) speed.
distance traveled
time of travel
• When unbalanced forces act on an object, the object
speeds up or slows down. This is
(86) acceleration.
Vocabulary – Lesson 18
• Newton’s three laws of motion
– First law of motion – (inertia) – tendency of
objects to maintain their motion when no
forces act on them.
– Second law of motion –
• Force = mass x acceleration
– Third law of motion – for every action, there is
an equal and opposite reaction. (Air blows in
one direction, car goes in other direction).
Lesson 19
Lesson 19
• Lesson 19
• If _________________,then __________
because _________________.
Question – Lesson 19
• How does the speed of a mousetrap car
change at .4 m intervals across a distance
of 2 meters?
• Lesson 19
•
•
•
•
Materials
1.
2.
3.
• Lesson 19
Time and Distance Data for the Mousetrap Car
Distance Position
Interval
(m)
Time
(s)
Trial 1
1
0.0 - 0.4
2
0.4 – 0.8
3
0.8 – 1.2
4
1.2 – 1.6
L 19
Trial 2
Trial 3
Avg.
Speed
(m/s)
Average
• Lesson 19
Lesson 20
L 20
Lesson 21
Lesson 21
• Lesson 21
• If _________________,then __________
because _________________.
• Lesson 21
•
•
•
•
Materials
1.
2.
3.
• Lesson 21
• Lesson 21
Vocabulary – Lesson 21
• When the car is at the top of the track, it has stored
energy. This is known as
(87) potential energy.
• As the car moves along the track, it has
(88) kinetic energy.
• When the car is at the highest point on the track, it has
its’ largest amount of
(89) gravitational potential energy.
Lesson 22