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Energy Unit Student Design Cover Page
(See directions on page 19)
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Energy Unit Front Page
At the end of this unit I will be able
to:
 Define and describe work.
 Describe the role of energy in
physical processes and living
organisms.
 Complete calculations of power,
energy, force, and work.
 Differentiate between potential
energy and kinetic energy.
 Use the law of conservation of
energy to predict kinetic energy,
potential energy, or velocity.
Quantities and units I will understand and use are:
 Quantities: Work, power, mechanical energy, kinetic energy, force, mass, velocity, distance
 Units: Joule, watt, newton, kilogram, m/s (meters per second), meters
The terms I will clearly define are:
 Efficiency, energy, fulcrum, joule, kinetic energy, law of conservation of energy, lever,
machine, mechanical advantage, mechanical energy, potential energy, power, pulley, watt,
work, work-energy theorem
The assignments I will have completed by the end of the unit are:
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Energy Unit Formulas, Quantities, and Units
Variables in equation:
W=Fd
P=W
t
Units for variable:
Misc. info
W=
(J)
F=
(N)
d=_
(m)
Variables in equation:
1 joule = 1 N  1 m
Units for variable:
P=
Misc. info
(W)*
W* =
(J)
t=
(s)
1 watt = 1 joule/sec
*Be careful!
Variables in equation:
Units for variable:
GPE =
GPE = mgh
KE =
(J)
m=
(kg)
g=
(m/s2)
h=
(m)
Variables in
equation:
½mv2
Misc. info
KE =
m=
v=
Units for variable:
Misc. info
(J)
(kg)
(m/s)
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Checking for Understanding: Work & Power
1. Compared to lifting one book, how much more work is done when lifting two books the
same distance?
2. Compared to lifting one book, how much more work is done when lifting two books twice as
far?
3. Which requires more work, lifting a 10-kg load a vertical distance of 2 m or lifting a 5-kg
load a vertical distance of 4 m?
4. How much power is required to do 100 J of work on an object in a time of 0.5 sec?
5. How much power is required to do 100 J of work on an object in a time of 1.0 sec?
6. Explain how work and impulse are similar and different. Write at least 3 complete
sentences. Include the units for both quantities in your explanation.
7. Two elevators do the same job of lifting 10 identical passengers up three floors, yet the
machines have different power outputs. How is this possible?
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Work & Power Notes
What is work?
Work is done when ____________________________________________________________
___________________________________________________________________________________
W=
Work is measured in _________________________________(J).
What is the unit for
work?
1 J = ________________________________________________________

Is holding a heavy
book considered
work?
Work is done ________________________________________:
o
A force is applied
o
_______________________________________________________
_______________________________________________________

If you _________________________________ you are ________________________
__________________________________________________________________________

The work that is done is on __________________________________________
__________________________________________________________________________
Power is __________________________________________________________________________
_____________________________________________________________________________________
P=
What is power?
Power is measured in __________________________________
1 watt =
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Simple Power/Work Calculations:
1. Calculate the work done when a 20-N force pushes a cart 3.5 m.
2. Calculate the work done in lifting a 500-N barbell 2.2 m above the floor.
3. Calculate the power expended when the barbell above is lifted 2.2 m in 2 s.
4. What work is done in lifting a 50-kg block to a height of 20 m?
5. What is the work done in raising a 20-kg package 60 cm vertically?
6. Determine the power expended when a barbell is raised 4.0 m in 2 seconds.
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Warm Up:
Jack and Jill ran up the hill. Jack is twice as massive as Jill; yet Jill
ascended the same distance in half the time.
a. Who did the most work? Use the space below to write out any relevant formulas and to
brainstorm, then answer the question at the bottom in well thought-out, complete
sentences!
b. Who delivered the most power? Use the space below to write out any relevant formulas and
to brainstorm, then answer the question at the bottom in well thought-out, complete
sentences!
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Calculating Power and Work
1. A person lifts a package weighing 75 N. If she lifts it 1.2 m off the floor, what work has she
done?
2. When 142 J of work is done in pushing a box horizontally 13.3 m, how much force is
applied?
3. What work is done when a person pushes a refrigerator weighing 720 N across a floor 12 m
if the force of friction between the refrigerator and the floor is 480 N?
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Calculating Power and Work
4. A student applies an upward force to lift a 129-kg barbell to a height of 1.98 m at a constant
speed. How much work is done?
5. On a recent adventure trip, Anita Break went rock-climbing. Anita was able to steadily lift
her 80.0-kg body 20.0 meters in 100 seconds. Determine Anita’s power rating during this
portion of the climb.
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Forms of Energy
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Energy Notes
Mechanical Energy (ME) is energy that ___________________________________
______________________________________________
What is mechanical energy
and what are the two
types?
Two types of mechanical energy:
1. ________________________________________________(PE) -- The energy
due to an object’s _______________________________
2. ________________________________________________ (KE) -- The energy
due to an object’s ________________________________
Energy is measured in ____________________

Potential energy is energy that has _______________________________
_________________________________________.
What is potential energy?

The energy is considered in a __________________________________.

__________________________________________________ in fuels, electric
batteries, and the food we eat is potential energy due to the
positions of the electrical charges at a submicroscopic level!

To elevate an object, ___________________ must be done to lift the
object against ___________________________________________________.

How much work must be done to elevate the object is also the
amount of PE it has!
What is gravitational

potential energy?
Gravitational potential energy is the energy ____________________
____________________________________________________

GPE =

GPE =

GPE =
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Energy Notes
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Energy Notes
•
If an object is moving, it can _____ _________________!
•
Kinetic energy is the ________________________________________, and
depends on the ____________________________________________________.
•
KE =
•
KE = Work required ______________________________________________
What is kinetic energy?
______________________________________________________________________
•
KE =
•
½ mv2 =
•
Whenever work is done, _______________________________________.
Law of conservation of energy:
Explain the law of
conservation of energy.
_______________________________________________________________________________
_______________________________________________________________________________
•
ME = KE + PE
•
The total ______________ is conserved, even if ___________ and
___________ change.
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Potential Energy & Kinetic Energy Venn Diagram
Warm Up:
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Checking for Understanding: Energy
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Energy Unit Study Guide
1. Circle “yes” or “no” to indicate whether work was done in each situation below. Then,
explain your answer.
a.
b.
c.
d.
e.
A teacher applies a force to a wall and becomes exhausted.
Explanation:
Yes or No?
A weightlifter lifts a barbell above her head.
Explanation:
Yes or No?
A waiter carries a tray full of meals across a dining room at a constant
speed. Explanation:
Yes or No?
A rolling marble hits a note card and moves it across a table.
Explanation:
Yes or No?
A shot-putter launches the shot.
Explanation:
Yes or No?
2. Two physics students are in the weightlifting room. Will lifts the 100-pound barbell over his
head 10 times in one minute; Ben lifts the 100-pound barbell over his head 10 times in 10
seconds.
a. Which student does the most work?
b. Which student delivers the most power?
3. Bart runs up a 2.91-meter high flight of stairs at a constant speed in 2.15 seconds. If Bart’s
mass is 65.9 kg, determine the work which he did and his power rating.
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Energy Unit Concept Map
(see page 19 for directions)
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Energy Unit Concept Cards
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Energy Unit Back Page
The California Dept. of Education Standards I have come to understand are:
 2.a. Students know how to calculate kinetic energy by using the formula E = (1/2)mv2.
 2.b. Students know how to calculate changes in gravitational potential energy near Earth by
using the formula (change in potential energy) =mgh (h is the change in the elevation).
 2.e. Students know momentum is a separately conserved quantity different from energy.
 2.g. Students know how to solve problems involving elastic and inelastic collisions in one
dimension by using the principles of conservation of momentum and energy.
 3.a. Students know heat flow and work are two forms of energy transfer between systems.
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