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Physics 432 Work and Energy
This worksheet was generated using questions from the www.physicsclassroom .com website . You can always
reference the Work and Energy Lessons for help.
Energy
1. Read each of the following statements and identify them as having to do with Kinetic Energy, Potential
Energy or Both.
Kinetic, Potential or Both
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Statement
If an object is at rest it does NOT possess this form of energy.
Depends upon object mass and height
The amount is expressed using the unit joule
If an object is at rest on the ground, it certainly does NOT possess this form
The energy an object possesses due to its motion
2. A toy car is moving along with 0.4 J of kinetic energy. If its speed is doubled, then its new kinetic
energy will be
a. 0.1 J
b. 0.2 J
r.'i .6 J
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c. 0.8 J
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3. A young boy's glider is soaring through the air with a kinetic energy of 0.2 J, possessing 0.8 J of
potential energy. If the wind does work to it and its speed is doubled and its height is doubled, the
new potential energy would be
a. 0.2 J
b. 0.4 J
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e. 0.8 J
d. 3.2 J
.6 J
The new kinetic energy would be ______~
b. O.4J
a. 0.2J
~.8J
4. Calculate the kinetic energy of a 5.2 kg object moving at 2.4
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d. 1.6 J
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5. Calculate the potential energy of a 5.2 kg object positioned 5.8 m above the ground.
6. Calculate the speed of a 5.2 kg object that possesses 26.1 J of kinetic energy.
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7. If an object moves in such a manner as to conserve its total energy, then the _ _ _ _ _ _ __
a. amount of kinetic energy remains the same throughout its motion
b. amount of potential energy remains the same throughout its motion
c.
amount of both potential energy and kinetic energy remain the same throughout its motion
@ sum of the potential energy and kinetic energy remain the same throughout its motion
8.
Calculate the total energy of a 5.2 kg object moving at 2.4 m/s and positioned 5.8 m above the ~ und.
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What would be the highest height that it could
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9. Work is
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What would be the fastest' speed it could have?
Work
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acting over some amount of
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10. Indicated wether or not the following represent examples of work:
Example
A teacher applies a force to a wall and becomes exhausted . A waiter carries a tray full of meals across a dining room at a constant speed A rolling marble hits a piece of clay and moves it across the table A weightlifter lifts barbells above her head.
Work Done?
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11. Which sets of units represent legitimate units for the quantity of work? Circle all correct answers .
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12. For each of situation calculate the amount of work done by the applied force.
A 100 N force is applied to move
a 15 kg object a horizontal
distance of 5 m.
A 100 N force is applied at an
angle of 30° to the horizontal
move a 15 kg a horizontal
distance of 5 m.
An upward force is applied to lift
a 15 kg object to a height of 5 m
at a constant speed.
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13. Before beginning its initial descent a roller coaster car is always pulled up the hill to a high initial
height. Work is done on the car - usually by a chain - to achieve the initial height. A coaster designer
is considering three different angles at which to drag a 2000 kg car to the top of a 60 m hill. Her big
question is: which angle would require the least amount of work? NOTE: The distance is longer for the
smaller angles because this distance represents the distance the chain will be pulling on the force for.
Angle of the Hill
35°
45°
55°
Work
Distance
105 m
84.9 m
73.2 m
Force Applied
4
1.5 x 10 N
4
1.41 x 10 N
1.64 x 104 N
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14. Determine the amount of work done in the following situations:
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a. Jim Neysweeper is applying a 21.6 N downward at an angle of 57.2° with the horizontal to
displace a broom a distance of 6.28 m.
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b. Ben Pumpiniron applies an upward force to lift a 129 kg barbell to a heig'li't of 1.98 m at a
constant speed.
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