Multiple Choice
Identify the choice that best completes the statement or answers the question.
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1.
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A first-class lever has the
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a.
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fulcrum at one end and the output force between the fulcrum and the input force. |
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b.
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fulcrum at one end and the input force between the fulcrum and the output force. |
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c.
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fulcrum in the middle. |
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d.
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input force in the middle. |
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2.
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A wheelbarrow is an example of a
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a.
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first-class lever. |
c.
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third-class lever. |
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b.
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second-class lever. |
d.
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fourth-class lever. |
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3.
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Which of the following is an example of a third-class lever?
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a.
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a nutcracker |
c.
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a crow bar |
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b.
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a hand-held boat paddle |
d.
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a screw |
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4.
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What is the mechanical advantage of a single movable pulley?
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5.
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A pair of tweezers is
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a.
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a first-class lever. |
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b.
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a compound machine made of two third-class levers. |
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c.
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a compound machine made of two second-class levers. |
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d.
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a kind of wedge. |
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6.
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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
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a.
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power. |
c.
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distance. |
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b.
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work. |
d.
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mechanical advantage |
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7.
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_____ is defined as the rate at which work is done.
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a.
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Power |
b.
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Joule |
c.
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Speed |
d.
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Mechanical advantage |
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8.
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A ramp is a _____ that decreases the force required to move an object while increasing the distance the object travels.
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a.
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force |
b.
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load |
c.
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newton |
d.
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machine |
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9.
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Lifting a car using a car jack is easier because it requires
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a.
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less force. |
b.
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less work. |
c.
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less time. |
d.
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None of the above |
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10.
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What are the two families of simple machines?
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a.
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wedge and compound |
c.
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inclined plane and lever |
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b.
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first class and second class |
d.
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pulley and screw |
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11.
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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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a.
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two |
b.
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three |
c.
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four |
d.
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five |
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12.
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A wedge is a modified
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a.
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wheel and axle. |
c.
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inclined plane. |
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b.
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pulley. |
d.
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lever. |
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13.
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A ramp is a simple inclined plane that allows one to apply an input force _____ the output force.
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a.
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perpendicular to |
c.
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greater than |
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b.
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equal to |
d.
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less than |
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14.
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Which of the following is an example of a compound machine?
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a.
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scissors |
c.
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wheel and axle |
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b.
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ax blade |
d.
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screw |
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15.
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What is the mechanical advantage of a single, fixed pulley?
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16.
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_____ is a measure of the ability to do work.
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a.
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Photosynthesis |
b.
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Power |
c.
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Respiration |
d.
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Energy |
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17.
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At the top of its arc, a thrown ball has _____ potential energy.
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a.
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maximum |
b.
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minimum |
c.
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zero |
d.
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average |
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18.
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As a dropped penny falls toward the ground, _____ energy is converted to _____ energy.
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a.
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thermal, potential |
c.
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kinetic, heat |
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b.
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kinetic, vibrational |
d.
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potential, kinetic |
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19.
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A dropped racquetball will not return to its original position because
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a.
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potential energy is inefficient. |
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b.
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the mechanical energy is stored up for later bounces. |
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c.
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some of the mechanical energy is converted to nonmechanical energy. |
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d.
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energy is not conserved. |
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20.
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The law of conservation of energy states that energy
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a.
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is created from motion. |
c.
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is always equal and opposite. |
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b.
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cannot be created or destroyed. |
d.
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can only be converted into heat. |
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21.
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_____ is the ratio of useful work output to work input.
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a.
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Potential energy |
c.
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Kinetic energy |
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b.
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Efficiency |
d.
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Power |
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22.
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A boy pushes on a parked car with a force of 200 N. The car does not move. How much work does the boy do on the car?
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a.
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200 N |
c.
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zero |
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b.
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200 L |
d.
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None of the above |
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23.
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What are the units of work?
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a.
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J |
c.
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kg • m2/s2 |
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b.
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N • m |
d.
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All of the above |
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24.
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A machine is a device that
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a.
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requires less work to do a given task. |
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b.
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decreases the amount of work done by a given force. |
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c.
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increases energy. |
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d.
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can multiply and change the direction of an input force. |
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25.
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What is the mechanical advantage of a single, fixed pulley?
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26.
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An inclined plane
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a.
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changes the direction of the force only. |
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b.
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changes the magnitude of the force only. |
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c.
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changes both the magnitude and the direction of the force. |
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d.
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decreases the amount of work done. |
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27.
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Which of the following is a compound machine?
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a.
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a wheel and axle |
c.
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a pair of scissors |
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b.
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a pulley |
d.
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a ramp |
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28.
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The primary source of the sun’s energy is
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a.
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chemical energy. |
c.
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nuclear fission. |
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b.
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nuclear fusion. |
d.
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potential energy. |
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29.
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Which of the following processes requires the most work?
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a.
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A 10 kg weight rests on a table. |
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b.
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A person holds a 1 kg weight still with outstretched arms. |
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c.
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A person lifts a 1 kg weight 1 m off the floor. |
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d.
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A 10 kg ball is rolled across the floor at a constant speed for a distance of 10 m. |
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30.
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A man pushes a crate along a factory floor by exerting a force of 55 N. If the crate moves a distance of 4.0 m, how much work does the man perform?
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a.
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165 N |
b.
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220 N |
c.
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zero |
d.
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145 J |
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31.
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What are the units of power?
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a.
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watts |
c.
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joules per second |
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b.
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horsepower |
d.
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All of the above |
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32.
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Which of the following is not a simple machine?
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a.
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a lever |
c.
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a screw |
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b.
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a pair of scissors |
d.
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a wheel and axle |
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33.
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Which of the following is an example of a wheel and axle?
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a.
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a block and tackle |
c.
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a screwdriver |
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b.
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a pulley |
d.
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a nutcracker |
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34.
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Which of the following is not in the inclined plane family?
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a.
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a wedge |
c.
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a ramp |
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b.
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a screw |
d.
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a wheel and axle |
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35.
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Which of the following statements about work and energy is not true?
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a.
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When work is done, energy is transferred or transformed. |
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b.
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Energy may be defined as the ability to do work. |
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c.
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Work and energy are always equal. |
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d.
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Work and energy have the same units. |
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36.
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Gravitational potential energy depends on
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a.
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the mass of the object. |
c.
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the acceleration due to gravity. |
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b.
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the height of the object. |
d.
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All of the above |
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Matching
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Match each item with the correct statement below.
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a.
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block and tackle |
c.
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wheel and axle |
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b.
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wheelbarrow |
d.
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screw |
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37.
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a lever or pulley connected to a shaft
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38.
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an example of a second-class lever
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39.
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an inclined plane wrapped around a cylinder
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40.
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multiple pulleys put together in a single unit
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Match each item with the correct statement below.
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a.
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potential energy |
c.
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kinetic energy |
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b.
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nonmechanical energy |
d.
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mechanical energy |
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41.
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the sum of an object’s kinetic and potential energies
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42.
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the energy due to motion
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43.
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the energy of an object due to its position, shape, or condition
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44.
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energy that lies at the level of atoms and that does not affect motion on a large scale
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