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Energy Web Review
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. What is a change from one form of energy to another called?
a. energy change
c. energy conversion
b. conversion of power
d. energy transfer
____
2. Whenever one form of energy is converted into another form of energy, some of the original energy is
always converted into which of the following?
a. light energy
c. kinetic energy
b. thermal energy
d. sound energy
____
3. When is the potential energy the greatest in a roller coaster?
a. at the bottom of the first hill
c. at the top of the second hill
b. at the top of the first hill
d. at the bottom of the second hill
____
4. After an energy conversion, you end up with the same total amount of energy as the original amount of
potential energy. Which of the following laws explains this rule?
a. law of energy changes
c. law of power and energy
b. law of conservation of energy
d. law of potential energy
____
5. Which of the following is true at the point where you reach the top of your jump on a trampoline?
a. The mechanical energy is zero.
b. The potential energy is at a maximum.
c. The kinetic energy and potential energy are equal.
d. The potential energy is zero.
____
6. What is the ability to do work called?
a. movement
b. energy
c. power
d. force
7. What is the energy of motion called?
a. potential energy
b. mechanical energy
c. kinetic energy
d. force energy
____
Completion
Complete each statement.
Use the terms from the following list to complete the sentences below.
inclined plane
kinetic
input
second-class
fixed
rope segments
8. After you exert a force on an object, it then moves and has ____________________ energy.
Use the terms from the following list to complete the sentences below.
kinetic
machines
work
ideal machine
distance
9. Force times ____________________ is the formula to calculate work.
Use the terms from the following list to complete the sentences below
energy
kinetic energy
potential energy
mechanical energy
energy conversion
friction
fossil fuels
renewable
10. After a bow is stretched, it has ____________________.
11. The transfer of energy that results from applying a force over a distance is called ____________________.
12. If Gabriela pushes on a box with a 20-newton force, no work is done if the box does not
____________________.
13. The work Brandon does in lifting a rock is calculated by multiplying the weight of the rock by the change in
the ____________________ of the rock.
Short Answer
14. Why does a stretched bow have potential energy?
15. A juggler is juggling some bowling pins. What happens to the kinetic energy of the pins once they stop
moving?
16. Scientifically speaking, why are car crashes more dangerous at higher speeds than at lower speeds? (In
terms of the energy that we are studying)
17. Compare energy and work. What does one have to do with the other?
18. What is the difference between kinetic and potential energy? Can you describe an object that has both?
Essay
19. Mrs. Kent is placing boxes of books on some shelves. When she needs to place the same boxes on a higher
shelf, how is the gravitational potential energy of the boxes affected?
20. Why is it impossible to create a perpetual motion machine? (A machine that never stops or needs more
energy - once you started it, it goes for ever)
21. Explain the following statement: “Applying a force to an object does not necessarily give the object
energy.”
Energy Web Review
Answer Section
MULTIPLE CHOICE
1. ANS:
OBJ:
2. ANS:
OBJ:
3. ANS:
OBJ:
4. ANS:
OBJ:
5. ANS:
OBJ:
6. ANS:
OBJ:
7. ANS:
OBJ:
C
1
B
3
B
1
B
2
B
1
B
1
C
2
PTS:
1
DIF:
1
REF: 2
PTS:
1
DIF:
1
REF: 3
PTS:
1
DIF:
2
REF: 3
PTS:
1
DIF:
1
REF: 3
PTS:
1
DIF:
2
REF: 3
PTS:
1
DIF:
1
REF: 1
PTS:
1
DIF:
1
REF: 1
DIF:
2
REF: 1
OBJ: 1
PTS: 1
DIF:
10. ANS: potential energy
1
REF: 1
OBJ: 2
PTS: 1
11. ANS: work
DIF:
1
REF: 1
OBJ: 2
PTS: 1
12. ANS: move
DIF:
basic
REF: section 4.1
PTS: 1
13. ANS: height
DIF:
basic
REF: section 4.1
DIF:
basic
REF: section 4.1
COMPLETION
8. ANS: kinetic
PTS: 1
9. ANS: distance
PTS:
SHORT ANSWER
1
14. ANS:
The bow has potential energy because work was done on it to change its shape.
PTS: 1
15. ANS:
DIF:
2
REF: 1
OBJ: 2
The kinetic energy changes into potential energy.
PTS: 1
16. ANS:
DIF:
2
REF: 1
OBJ: 3
because speed has a greater effect on kinetic energy than mass does. Remember that velocity is
squared in the equation for kinetic energy.
PTS: 1
17. ANS:
DIF:
2
REF: 1
OBJ: 2
Energy is the ability to do work. Work cannot occur without energy.
PTS: 1
18. ANS:
DIF:
1
REF: 1
OBJ: 1
Kinetic energy is the energy of motion. Potential energy is the energy that an object has because
of the object’s position or shape A child’s swing has both kinetic and potential energy.
PTS:
1
DIF:
1
REF: 1
OBJ: 2
ESSAY
19. ANS:
The gravitational potential energy of the boxes will increase because she needs to raise the boxes
to a higher shelf. Remember that GPE = m x g x h. Since the mass and gravity are not changing
for the object, the only thing changing is the height as the boces are lifted.
PTS: 1
20. ANS:
DIF:
2
REF: 4
OBJ: 2
Answers may vary. Sample answers: Some wasted thermal energy always results from energy
conversions. The only way to keep a machine moving is to have a constant supply of energy.
PTS: 1
21. ANS:
DIF:
2
REF: 3
OBJ: 4
For mechanical energy to be transferred to an object, work must be done on the object. Work is
the product of force AND the distance the object moves in the direction of the applied force. It is
possible to apply a force on an object with no resulting movement. Unless the object moves when
the force is applied, no mechanical energy is absorbed by the object.
PTS:
1
DIF:
intermediate REF: section 4.1