# Review Key

```Name __________________________________ Period _____ Date ____________
IPC TEST REVIEW: WORK, ENERGY &amp; POWER
1. Stored energy or energy due to position is known as ____potential________________ energy.
2. The formula for calculating potential energy is __PE=mgh________________.
3. If weight of an object increases the GPE __increases______________; to increase the GPE you would
___increase___________ the object’s height.
4. Potential energy is measured in units of ____Joules___________.
5. Mass must be measured in units of ____kg___________.
6. The value of the g constant (the acceleration of all objects due to gravity) on earth is _9.8_m/s2_______.
7. Height must be measured in units of ____m___________.
8. Calculate the potential energy of a rock with a mass of 55 kg while sitting on a cliff that is 27 m high.
14,553J
9. What distance is a book from the floor if the book contains 196 Joules of potential energy and has a mass of
5 kg? 4 m
10. An automobile is sitting on a hill which is 20 m higher than ground level. Find the mass of the automobile if
it contains 362,600 J of potential energy. 1850 kg
11. Energy of motion is known as ____kinetic________________ energy.
12. The formula for calculating kinetic energy is ___KE=1/2mv2____________.
13. The two factors that determine the amount of kinetic energy in an object are
___mass_________________ and ____velocity________________.
14. Kinetic energy is measured in units of ___Joules____________.
15. Mass must be measured in units of ___kg____________.
16. Velocity must be measured in units of __m/s_____________.
17. Calculate the kinetic energy of the rock in problem #8 if the rock rolls down the hill with a velocity of 8
m/s. 1760 J
18. Calculate the kinetic energy of a truck that has a mass of 2900 kg and is moving at 55 m/s. 4,386,250J
21. The SI (metric) unit for energy is ___Joules______________ and the symbol is ____J______.
22. At what height is an object that has a mass of 50 kg if its gravitational potential energy is 9800 J?20.4m
23. What is the mass of an object if its gravitational potential energy is 3822 J and it is 15 m above the
ground?26g
24. Determine whether work is being done in each of the following examples:
a. a train engine pulling a loaded boxcar initially at rest yes
b. a tug of war that is evenly matched no
c. a crane lifting a car yes
25. A weight lifter lifts a set of weights a vertical distance of 2 m. If a constant net force of 350 N is exerted on
the weights, what is the net work done on the weights? 700 J
26. If 2 J of work is done in raising a 180 g apple, how far is it lifted? 1.13 m
27. If a neighbor pushes a lawnmower four times as far as you do but exerts only half the force, which one of
you does more work and by how much? Neighbor, twice as much
28. Grant stands 3 meters from the check out at the grocery store holding a 20 N bag of potatoes for 10
minutes. How much work does he perform? zero
29. A coconut falls out of a tree 12.0 m above the ground and hits a bystander 3.00 m tall on the top of the
head. It bounces back up 1.50 m before falling to the ground. If the mass of the coconut is 2.00 kg, calculate
the potential energy of the coconut relative to the ground at each of the following sites:
a. while it is still in the tree, 2235.2J
b. when it hits the bystander on the head, 58.8J
c. when it bounces up to its maximum height, 88.2J
d. when it lands on the ground, 0 J
31. The diagram below shows five points on a roller coaster.
a. List the points (a, b, c, d, e) in order from the point where the car has the greatest potential
energy to the point where the car has the least potential energy. A, E, B, D, C
b. Now, list the points in order from the point where the car has the greatest kinetic energy to the
point where the car has the least kinetic energy. C, B, D, E, A
c. How do your two lists relate to each other? Inversely related, opposite order
32. Using a jack, a mechanic does 5450 J of work to lift a car in 50.0 s. What is the mechanic’s power output?
109 W
33. You and two friends apply a force of 425 N to push a piano up a 2.0 m long ramp. If you make it to the top
in 5.0 s, what is your power output in watts?
170 W
34. A box having 2 kg mass, under the effect of forces F 1, F2 and F3, takes distance 5m. Which ones of the
forces do work?
F3
35. Identify the form of energy shown in each of the following pictures:
__elastic__________
__chemical__________
__kinetic_________________
__gravitational______
```