Name
Period
Date
Energy: Review Worksheet
1. Which of the following statements are true about kinetic energy?
a. Kinetic energy is the energy storage mechanism that depends upon the position
of an object.
b. If an object is at rest, then it does not have any kinetic energy.
c. If an object is on the ground, then it does not have any kinetic energy.
d. The kinetic energy of an object is dependent upon the mass and the speed of an
object.
e. Faster moving objects always have a greater kinetic energy.
f. More massive objects always have a greater kinetic energy.
g. Kinetic energy is a scalar quantity.
h. An object has a kinetic energy of 40 J. If its mass were twice as much, then its
kinetic energy would be 80 J.
i. An object has a kinetic energy of 40 J. If its speed were twice as much, then its
kinetic energy would be 80 J.
j. Object A has a mass of 1 kg and a speed of 2 m/s. Object B has a mass of 2 kg
and a speed of 1 m/s. Objects A and B have the same kinetic energy.
k. An object can never have a negative kinetic energy.
l. A falling object always gains kinetic energy as it falls.
m. A 1 kg object is accelerated from rest to a speed of 2.0 m/s. This object gains
4.0 Joules of kinetic energy.
2. Which of the following statements are true about gravitational potential energy?
a. Moving objects cannot have gravitational potential energy.
b. Gravitational potential energy is the energy stored due to an object’s position in a
gravitational field.
c. Gravitational potential energy is dependent upon the mass of an object.
d. If the mass of an elevated object is doubled, then its gravitational potential
energy will be doubled as well.
e. Gravitational potential energy is decreased as objects free-fall to the ground.
f. The higher that an object is, the more gravitational potential energy it will have.
g. The unit of measurement for gravitational potential energy is the Joule.
h. A 1 kg mass at a height of 1 meter has a potential energy of 1 Joule.
i. A 1 kg object falls from a height of 10 m to a height of 6 m. The final potential
energy of the object is approximately 40 J.
Energy: Review WS
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3. Which of the following statements are true about elastic potential energy?
a.
b.
c.
d.
Elastic potential energy is dependent upon the mass of an object.
Elastic potential energy is the energy stored in a stretched or compressed spring.
Elastic potential energy is dependent on the spring constant of the spring.
A stretched spring has 10 J of elastic potential energy. If the spring is stretched
twice as far, it will now store 40 J of elastic potential energy.
e. The unit of measurement for elastic potential energy is the Joule.
4. Which of the following statements are true about work? Include all that apply.
a. Work is the transfer of energy into or out of a system by means of an external
force.
b. A Watt is the standard metric unit of work.
c. Units of work would be equivalent to a Newton times a meter.
2
d. A kgm 2 would be a unit of work.
s
e. Work is a time-based quantity; it is dependent upon how fast a force displaces
an object.
f. Superman applies a force on a truck to prevent it from moving down a hill. This
is an example of work being done.
g. An upward force is applied to a bucket as it is carried 20 m across the yard. This
is an example of work being done.
h. A force is applied by a chain to a roller coaster car to carry it up the hill of the first
drop of the Shockwave ride. This is an example of work being done.
i. A force acts upon an object to push the object along a surface at constant
speed. By itself, this force must NOT be doing any work upon the object.
j. A force acts upon an object at a 90 degree angle to the direction that it is moving.
This force is doing negative work upon the object.
k. An individual force does NOT do positive work upon an object if the object is
moving at constant speed.
l. An object is moving to the right. A force acts leftward upon it. This force is doing
negative work.
Energy: Review WS
Page 3
5. Which of the following statements are true about power?
a. Power is a time-based quantity.
b. Power refers to how fast work is transferred into or out of a system.
c. Powerful people or powerful machines are simply people or machines which
always do a lot of work.
d. A force is exerted on an object to move it at a constant speed. The power
delivered by this force is the magnitude of the force multiplied by the speed of
the object.
e. The standard metric unit of power is the Watt.
f. If person A and person B do the same job but person B does it faster, then
person A does more work but person B has more power.
g. The Newton•meter is a unit of power.
h. A 60 kg boy runs up a 2.0 meter staircase in 1.5 seconds. His power is
approximately 80 Watt.
i. A 300 N force is applied to a skier to drag her up a ski hill at a constant speed of
1.5 m . The power delivered by the toe rope is 450 Watts.
s
6. Rank these four objects in increasing order of kinetic energy, beginning with the
smallest.
Object A
Object B
Object C
Object D
m = 5.0 kg
v  4.0 m
s
yi  2.0 m
m = 10.0 kg
v  2.0 m
s
yi  3.0 m
m = 1.0 kg
v  5.0 m
s
yi  5.0 m
m = 5.0 kg
v  2.0 m
s
yi  4.0 m
7. Rank these four objects in increasing order of gravitational potential energy,
beginning with the smallest.
Object A
Object B
Object C
Object D
m = 5.0 kg
v  4.0 m
s
yi  2.0 m
m = 10.0 kg
v  2.0 m
s
yi  3.0 m
m = 1.0 kg
v  5.0 m
s
yi  5.0 m
m = 5.0 kg
v  2.0 m
s
yi  4.0 m
Energy: Review WS
Page 4
8. Consider the following physical situations. For each case, define a system. Then
indicate whether there is positive (+), negative (-) or no (0) work being done on the
system.
Description of Physical Situation
+, -, or no (0) Work
a. A cable is attached to a bucket and the force of tension is
used to pull the bucket out of a well.
System
b. Rusty Nales uses a hammer to exert an applied force upon
a stubborn nail to drive it into the wall.
System
c. Near the end of the Shockwave ride, a braking system
exerts an applied force upon the coaster car to bring it to a
stop.
System
d. The force of friction acts upon a baseball player as he
slides into third base.
System
e. A busy spider hangs motionless from a silk thread,
supported by the tension in the thread.
System
f. In baseball, the catcher exerts an abrupt applied force upon
the ball to stop it in the catcher's mitt.
System
g. In a physics lab, an applied force is exerted parallel to a
plane inclined at 30 degrees in order to displace a cart up the
incline.
System
h. A pendulum bob swings from its highest position to its lowest
position under the influence of the force of gravity.
System
9. The following data was collected for an ideal spring.
Energy: Review WS
Page 5
Force exerted by a spring (N)
12
10
8
6
4
0
0.20 0.40 0.60 0.80 1.0
Elongation (m)
1.2
1.4
a. What is the spring constant of this
spring?
b. Write a Hooke’s Law equation for this
ideal spring. Be sure to use the correct
variables and units.
c. How much force would the spring
exert if it was stretched to 2.0 m?
d. How much elastic potential energy
would be stored if the spring was
stretched to 0.80 m ?
10. A 1000. kg car is traveling at a speed of 30. m
when the driver slows to a stop.
s
a. Complete the Energy Bar Graph / Flow Diagram quantitatively.
System =
Initial
Ek Eg Ee
0
Energy Flow
Diagram
Ek
Final
Eg Ee E d i s s
0
b. If the car stops in 100. m , what is the average braking force applied to the car?
Energy: Review WS
Page 6
11. A 1.0 kg calico kitten jumps down from a 2.0 m high fence.
a. What is the kitten's E g ?
b. What will be the kitten's speed when it reaches the ground? Complete the
Energy Bar Graph / Flow Diagram quantitatively.
System =
Initial
Ek Eg Ee
Energy Flow
Diagram
0
Ek
Final
Eg Ee E d i s s
0
12. A 50. g dart rests up against a vertical spring of spring constant 1000. N
which has
m
been compressed 0.050 m . How fast would the dart be moving when it reaches a
height of 1.0 m ? Complete an Energy Bar Graph / Flow Diagram quantitatively.
System =
Initial
Ek Eg Ee
0
Energy Flow
Diagram
Ek
Final
Eg Ee E d i s s
0
13. A man of mass 81.6 kg climbs a ladder to his 5.0 m high roof.
Unit VII Energy: Review
Page 7
a. How much work is done by the man
while climbing to his roof?
b. How much power is required to climb to
his roof in 45 s?
On his second trip up the ladder he carries a 20. kg package of shingles.
a. Calculate the work done as he
b. How much power is required if this
climbs to his roof with the shingles.
second trip takes 90. s ?
vf  0
14. A 2.40 kg box on a frictionless incline is
against a spring of spring constant 15 N
m
that is compressed 0.784 m . Once the
box is released, how far above its release
height does it move before coming to a
stop?
vi  0
25 kg
 k  0.30

FA  175 N
yf  ?
Energy: Review WS
Page 8
15. A 25 kg box is dragged from rest by a 175 N force as in the diagram.
a. Draw a force
b. Write an equation for
c. Calculate the force of
diagram for the box.
the vertical forces
friction between the
acting on the box and
surface and the box.
then calculate the
Normal force.
d. How much energy is dissipated in
pulling the box 3.5 m ?
e. How much energy is transferred while
pulling the box 3.5 m ?
f. How fast is the box moving after being dragged 3.5 m ? Complete the Energy
Bar Graph / Flow Diagram quantitatively.
System =
Initial
Ek Eg Ee
0
Energy Flow
Diagram
Ek
0
Final
Eg Ee E d i s s