Download WORK, ENERGY, AND ENERGY CONSERVATION

10,11
WORK, ENERGY, AND ENERGY CONSERVATION
Vocabulary Review: Write the term that correctly completes the statement. Use each term once.
power
joule
mechanical energy
law of conservation of energy
kinetic energy
work-energy theorem
gravitational potential energy
work
watt
1. _________________________
Within a closed, isolated system, energy can change form, but
the total amount of energy is constant. This is a statement of
the ____ .
2. _________________________
The sum of the kinetic and potential energy of a system is
the ____ of the system.
3. _________________________
The stored energy of an Earth-object system as a result of
gravitational attraction between the object and Earth is ____ .
4. _________________________
A ____ is a unit of power defined as 1 joule per second.
5. _________________________
The ____ is the SI unit used for work.
6. _________________________
The ____ states that the work done on an object equals the
change in energy of the object.
7. _________________________
The energy that results from the motion of an object is called
____.
8. _________________________
The rate at which energy is transformed is called ____.
9. _________________________
You can calculate ___ by multiplying force, the distance through
which the force is applied.
For each statement below, write true or rewrite the italicized part to make the statement true.
10. _________________________
Through the process of doing work, energy can move between
the external world and the system as the result of forces.
11. _________________________
In the equation W  Fd, it is assumed that the force varies and is
exerted in the direction of displacement.
12. List 3 examples of work being done on an object.
a. _______________________________________________
b. _______________________________________________
c. _______________________________________________
13. What two conditions must be met for work to be done?
a) __________________________________________________________________
b) __________________________________________________________________
Chapter 10,11  Work, Energy, and Energy Conservation
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Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
For each phrase on the left, write the letter of the matching item.
________
14. calculation of kinetic energy
________
15. calculation of work
a. W
b. Fd
c. ½ mv2
________
16. equivalent to N•m
d. W  E
________
e. J
________
17. statement that the work done on an object is equal
to the object’s change in energy
18. symbol for kinetic energy
________
19. symbol for work
f. KE
The force-displacement graph of a crate that was pushed
horizontally is shown at right. Refer to the graph to
answer the following questions.
20. How far did the crate move horizontally?
___________________________________
21. What was the magnitude of the force that
acted on the crate?
___________________________________
22. How much work was done in moving the
crate 0.50 m?
23. Calculate the amount of work done in moving the crate 0.20 m.
For each term on the left, write the letter of the matching item.
a. kW
________
24. calculation of power
________
25. rate of transforming energy
________
26. symbol for power
d. W/t
________
27. unit of power
e. watt
________
28. 1000 W
b. power
c. P
Chapter 10,11  Work, Energy, and Energy Conservation
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Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Circle the letter of the choice that best completes the statement or answers the question.
29. A baseball and a ping pong ball are both shot from a slingshot with equal velocity. Which object
has the greater kinetic energy from this motion?
A .the baseball
c.The answer depends on the launch angle.
b. the ping pong ball
d.The kinetic energies are equal.
30. How does the kinetic energy from the forward motion of a car traveling at 16 m/s compare with
the kinetic energy of the same car traveling at 8 m/s?
a.It is 2 times greater.
c.It is 8 times greater.
b.It is 4 times greater.
d.It is 16 times greater.
31. A 6 kg ball is traveling at 5 m/s. What is its kinetic energy?
a.37.5 J
c. 150 J
b.75 J
d. 300 J
32. If the velocity of the ball in question 32 doubles, its kinetic energy will be ____ .
a.37.5 J
c. 150 J
b.75 J
d. 300 J
33. A ball of mass 0.5 kg has 100 J of kinetic energy. What is the velocity of the ball?
a.20 m/s
c. 100 m/s
b.40 m/s
d. 400 m/s
34. A ball traveling at 30 m/s has 900 J of kinetic energy. What is the mass of the ball?
a.1 kg
c. 9 kg
b.2 kg
d. 30 kg
35. You are designing a skateboard park. The starting ramp is 0.61 m high.
a. What would be the gravitational potential energy for a 63.5-kg skateboarder at the top of
the starting ramp?
b. Assume that the same 63.5-kg skateboarder in part a falls off the side of the ramp. What is
the kinetic energy from the skateboarder’s falling motion just before she reaches the
ground? Hint: Think about the type of energy they will have right before reaching
ground.
Chapter 10,11  Work, Energy, and Energy Conservation
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Use the diagram at right to answer the following questions. Note that the string attached to box at position A is cut
and the box dropped.
36. The point at which the block has both
kinetic and potential energy is ____ .
A
B
C
37. The block has the maximum amount of
kinetic energy at point ____ .
A
B
C
38. At point A prior to the box being dropped, the block has ____ .
a. no energy
b. both kinetic and potential energy
c. only kinetic energy
d. only potential energy
39. If the block has 200 J of potential energy at point A how much and what types of energy will it
have at point B (Point B is ½ way down)
40. Draw a graph that represents the change in KE and PE of a pendulum.
Energy
Time
41. What does the slope of the graph to the right represent?
___________________________________________________
42. Calculate Power based on the information given in the graph
to the right. Show Your Work!!!
Chapter 10,11  Work, Energy, and Energy Conservation
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43. A force does work on an object if the component of force is _________________ to the
displacement.
44. An empty coffee mug with a mass of 0.40kg falls off a table and hits the floor with 10 J of
energy, how high was the table? Show your work!
45. If 80 joules of work is done moving a cart a distance of 5 m, how much force is applied? Show
your work!
46. What is the average Power of a 200N athlete running up a flight of stairs rising vertically 4.0m in
5 sec? Show your work!
47. A jet skier is traveling 14 m/s and has 8.2 x 103 joules of energy. What is its mass? Show your
work!
48. What is the gravitational potential energy relative to the ground of a 0.25-kg ball resting at the
edge of a roof that is 35 m above the ground? Show your work!
49. How high can a worker lift a 35.00-kg bag of sand if he uses 35000. J of energy? Show your
work!
Chapter 10,11  Work, Energy, and Energy Conservation
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Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.