Name: ____________________
Physics 644
Date:____/____/____
Review: Energy KEY
Energy
1. What does kinetic energy depend upon? (choose between: speed or height)
Kinetic energy depends upon speed and mass.
2. What does potential energy depend upon? (choose between: speed or height)
Potential energy depends upon mass (or weight) and height.
3. Can an object that is at rest have energy? Give an example to support your answer.
Yes, an object that is at rest can have energy. For example a
coyote standing at the end of a clift would have potential
energy because he has the potential to fall, but he is not
moving.
4. What kind of energy does an apple that is hanging (at rest) in a tree have?
An apple hanging from a tree has gravitational potential energy
or PE, because it is above the ground.
5. What kind of energy does an apple that has fallen out of a tree have just before it hits
the ground?
An apple that has fallen out of the tree, just about hitting the
ground has kinetic energy because it is moving.
6. Which has more potential energy: a 25 N kitten that is sitting on the counter 1 m above
the ground or a 50 N cat who is also 1 m above the ground?
A 50 N cat has more PE than a 25 N kitten, because it has more
weight (or mass). PE depends on weight and height.
7. Which has more potential energy: a 50 N cat that is 1 m above the ground or a 50 N cat
who has climbed a tree and is 10 m above the ground?
A 50 N cat that has climbed to a tree 10 m above the ground
ahs more PE. This is because it is higher. PE depends on height
and weight.
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8. Find the equation for kinetic energy on your MCAS formula sheet and copy it into the
space below:
KE =
KE = 1/2 m v2
1
2
mv2
9. Which has more kinetic energy: a mouse who is running at 2 m/s or a cat who is
running at 2 m/s?
A cat running at 2 m/s has more KE that a mouse running at the
same speed. KE is directly proportional to the mass, the more
mass, the more KE.
10. Which has more kinetic energy: a 5 kg cat who is walking at 1 m/s or a 5 kg cat who is
running at 3 m/s?
A 5 kg cat running at 3 m/s has more KE that a cat running at 1
m/s. KE is directly proportional to speed. The more speed, the
more KE.
MCAS Questions: The following questions are taken from past MCAS exams. Please
circle the correct answer for multiple choice questions.
11. (2004, grade 9, #17)
A skateboarder travels from location 1 to location 4 as shown below
At which location does the skateboarder have the most kinetic energy and the least
potential energy?
A. 1
B. 2
C. 3
D. 4
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12. (2005, grade 8, #9)
The diagram below represents a diver’s motion from the top of a high diving board into
a pool of water.
At which labeled point does the diver have the least potential energy?
A. 1
B. 2
C. 3
D. 4
13. (2006, grade 9, #31)
Which of the following describes the mechanical energy of a cart at rest at the top of a
steep hill?
A. The cart has no mechanical energy.
B. The cart’s mechanical energy is all kinetic.
C. The cart’s mechanical energy is all potential.
D. The cart’s mechanical energy is half potential and half kinetic.
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