Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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What is the mechanical advantage of a ramp that is 10 meters long and 2 meters
high?
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2.
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A first-class lever has the
a. | fulcrum at one end and the output force between the fulcrum and the input
force. | b. | fulcrum at one end and the input force between the fulcrum and the output
force. | c. | fulcrum in the middle. | d. | input force in the
middle. |
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3.
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A wheelbarrow is an example of a
a. | first-class lever. | c. | third-class lever. | b. | second-class lever. | d. | fourth-class
lever. |
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4.
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Which of the following is an example of a third-class lever?
a. | a nutcracker | c. | a crow bar | b. | a hand-held boat paddle | d. | a screw |
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5.
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What is the mechanical advantage of a single movable pulley?
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6.
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A pair of tweezers is
a. | a first-class lever. | b. | a compound machine made of two third-class
levers. | c. | a compound machine made of two second-class levers. | d. | a kind of
wedge. |
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7.
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The transfer of energy to a body by the application of a force that causes the
body to move in the direction of the force is called
a. | power. | c. | distance. | b. | work. | d. | mechanical
advantage |
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8.
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A boy exerts an average force of 65 N when he lifts a box 1.2 meters. How much
work does he do?
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9.
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_____ is defined as the rate at which work is done.
a. | Power | c. | Speed | b. | Joule | d. | Mechanical
advantage |
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10.
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How much power is required to do 180 J of work in 2.4 s?
a. | 7.5 W | c. | 178 W | b. | 75 W | d. | 430 W |
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11.
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How much power is required to lift a 30.0 N chair 0.20 m in 2.0 s?
a. | 1.0 W | c. | 12 W | b. | 3.0 W | d. | 15 W |
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12.
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Calculate the mechanical advantage of a wrench that allows you to move a bolt
0.01 m by moving the handle 0.50 m.
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13.
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A ramp is a _____ that decreases the force required to move an object while
increasing the distance the object travels.
a. | force | c. | newton | b. | load | d. | machine |
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14.
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What is the mechanical advantage of a ramp 2.0 m long and 0.50 m tall?
a. | 1.0 | c. | 4.0 | b. | 2.5 | d. | None of the
above |
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15.
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A pulley with a mechanical advantage of 5.00 is used to lift a bucket weighing
285 N. How much force must be used to lift the bucket?
a. | 57.0 N | c. | 285 N | b. | 280 N | d. | 1,425 N |
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16.
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Lifting a car using a car jack is easier because it requires
a. | less force. | c. | less time. | b. | less work. | d. | None of the
above |
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17.
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What are the two families of simple machines?
a. | wedge and compound | c. | inclined plane and lever | b. | first class and
second class | d. | pulley and
screw |
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18.
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Levers are divided into _____ classes based on the location of the fulcrum and
of the input and output forces.
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19.
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A wedge is a modified
a. | wheel and axle. | c. | inclined plane. | b. | pulley. | d. | lever. |
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20.
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A ramp is a simple inclined plane that allows one to apply an input force _____
the output force.
a. | perpendicular to | c. | greater than | b. | equal to | d. | less than |
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21.
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Which of the following is an example of a compound machine?
a. | scissors | c. | wheel and axle | b. | ax blade | d. | screw |
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22.
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What is the mechanical advantage of a single, fixed pulley?
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23.
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_____ is a measure of the ability to do work.
a. | Photosynthesis | c. | Respiration | b. | Power | d. | Energy |
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24.
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Calculate the gravitational potential energy relative to the ground when an 82
kg person climbs to the top of a 2.0 m stepladder.
a. | 164 J | c. | 402 J | b. | 3.3 ´
102 J | d. | 1.6 ´ 103 J |
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25.
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What is the kinetic energy of a 1.40 kg discus with a speed of 22.5 m/s?
a. | 15.8 J | c. | 354 J | b. | 31.5 J | d. | 709 J |
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26.
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When a pitcher throws a softball to a catcher, the vibration of the atoms that
make up the softball is _____ energy, while the motion of the ball toward the catcher is _____
energy.
a. | nonmechanical, mechanical | c. | electrical,
thermal | b. | potential, nonmechanical | d. | mechanical, chemical |
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27.
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A dog running at a speed of 12 m/s has 1,080 J of kinetic energy. What is the
mass of the dog?
a. | 7.5 kg | c. | 30 kg | b. | 15 kg | d. | 45 kg |
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28.
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An astronaut with a mass of 91 kg is 0.30 m above the moon’s surface. The
astronaut’s potential energy is 46 J. Calculate the free-fall acceleration on the moon.
a. | 0.15 m/s2 | c. | 6.6 m/s2 | b. | 1.7 m/s2 | d. | 9.8
m/s2 |
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29.
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At the top of its arc, a thrown ball has _____ potential energy.
a. | maximum | c. | zero | b. | minimum | d. | average |
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30.
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As a dropped penny falls toward the ground, _____ energy is converted to _____
energy.
a. | thermal, potential | c. | kinetic, heat | b. | kinetic, vibrational | d. | potential,
kinetic |
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31.
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A dropped racquetball will not return to its original position because
a. | potential energy is inefficient. | b. | the mechanical energy is stored up for later
bounces. | c. | some of the mechanical energy is converted to nonmechanical
energy. | d. | energy is not conserved. |
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32.
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The law of conservation of energy states that energy
a. | is created from motion. | c. | is always equal and
opposite. | b. | cannot be created or destroyed. | d. | can only be converted into
heat. |
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33.
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Mechanical energy can change to nonmechanical energy as a result of
a. | air resistance. | c. | radiation. | b. | heat. | d. | None of the
above |
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34.
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A system that receives energy from external sources is called
a. | open. | c. | compound. | b. | closed. | d. | efficient. |
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35.
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_____ is the ratio of useful work output to work input.
a. | Potential energy | c. | Kinetic energy | b. | Efficiency | d. | Power |
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