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2.2 lbs = 9.8 N = 1 kg
1 m = 3.28 ft
g = 9.8 m/s2
Review for Unit 5 Test
Use this review as a GUIDE for studying. Remember to study the notes as well as your Work &
Power Quiz.
1. Define the following terms
Energy
Kinetic Energy
Potential Energy
Work
Power
Law of Conservation
of Energy
Energy
Transformation
Energy Transfer
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2. List the equations and units for the following
Equation(s)
Unit(s)
Work
Power
Kinetic Energy
Potential Energy
(2 equations!)
Velocity
(using KE)
3. Identify the relationship between the following as being inversely or directly proportional.
Proportional (Circle One)
Work and Force
Inversely
Directly
Work and Distance
Inversely
Directly
Power and Work
Inversely
Directly
Power and Distance
Inversely
Directly
Power and Force
Inversely
Directly
Power and Time
Inversely
Directly
PE and Mass
Inversely
Directly
PE and Height
Inversely
Directly
KE and Mass
Inversely
Directly
KE and Speed
Inversely
Directly
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4. Give at least one example of one object that has each of the following types of energy
Object(s)
Electrical
Mechanical
Chemical
Solar
Light
Sound
Nuclear
Elastic
5. Give at least one example of an object that has the following energy transformations.
Object(s)
Electrical to Mechanical
Mechanical to Electrical
Electrical to Heat
Chemical to Light
Chemical to Electrical
Electrical to Sound
Solar to Electrical
Elastic (Potential) to Kinetic
6. 100 J of energy is put into a system. 68 J comes out of the system as mechanical energy. How
much was “lost” to heat energy? How do you know?
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7. As an object falls, what happens to the potential energy? Kinetic energy?
8. If you push on a wall and it doesn’t move, you are not doing work on the wall. Why?
9. What has to be true about force and distance in order for work to be done?
10. Does KE depend more on speed or mass? Why?
11. Calculate the work and power when lifting a 50 kg bag to a height of 5 m in a time of 2 seconds.
12. If a father lifts his child 2.3 m into the air and exerts a force of 210 N, what is the work done by
the dad?
13. The dad lifts the child (#12) in 4 seconds. What is his power?
14. If the dad lifted the child in half the time, how would the new power compare to the original?
What about if he lifted the child in twice the amount of time? (Hint: say if the power increases or
decreases and also by how much!)
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15. A moving car has kinetic energy. If it speeds up until it is going 3 times the original speed, how
much kinetic energy does it have compared to the original?
16. A dog is traveling at 3 m/s. If the mass of the dog is 30 kg, what is the KE of the dog?
17. What is the potential energy of a 120 lbs skier at the top of a 400 m mountain?
18. What is the mass (kg) of an object that has a potential energy of 25.5 J at a height of 2.4 ft?
19. A cheetah has an average weight of 110 lbs and an average kinetic energy of 7998 J. What is
the average speed of a cheetah?
20. A constant force of 240 N is exerted on a box to move it across the floor. If 1800 J of work is
done on the box, how far did the box move?
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