Download Physical Science Chapter 12

Physical Science Chapter 12 Practice Test
Name_____________________
Modified True/False
Indicate whether the sentence or statement is true or false. If false, change the identified word or phrase to make the
sentence or statement true.
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1. If a person tries to lift a heavy box for 5 seconds and can’t make it budge, the work done on the box is less
than zero. _________________________
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2. Machines decrease the amount of energy that is needed to do work. _________________________
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3. Because of friction, using machines increases the amount of energy that is needed to do work
_________________________
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4. An arrangement of multiple pulleys causes the direction of the output force to be opposite to the direction of
the input force. _________________________
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
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5. What are the units of work?
a. J
c. kgm2/s2
b. Nm
d. All of the above
6. Which of the following processes requires the most work?
a. A 10 kg weight rests on a table.
b. A person holds a 1 kg weight still with outstretched arms.
c. A person lifts a 1 kg weight 1 m off the floor.
d. A 10 kg ball is rolled across the floor at a constant speed for a distance of 10 m.
7. What are the units of power?
a. watts
c. joules per second
b. horsepower
d. All of the above
8. A machine is a device that
a. requires less work to do a given task.
b. decreases the amount of work done by a given force.
c. increases energy.
d. can multiply and change the direction of an input force.
9. 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.
10. A wheelbarrow is an example of a
a. first-class lever.
c. third-class lever.
b. second-class lever.
d. fourth-class lever.
11. Which of the following is an example of a wheel and axle?
a. a block and tackle
c. a screwdriver
b. a pulley
d. a nutcracker
____ 12. Which of the following is not in the inclined plane family?
a. a wedge
c. a ramp
b. a screw
d. a wheel and axle
____ 13. Which of the following statements about work and energy is not true?
a. When work is done, energy is transferred or transformed.
b. Energy may be defined as the ability to do work.
c. Work and energy are always equal.
d. Work and energy have the same units.
____ 14. What is the gravitational potential energy of a 55 kg box that is 8.0 m above the ground?
a. 5500 J
c. 4300 J
b. 3400 J
d. 550 J
____ 15. Gravitational potential energy depends on the
a. the mass of the object.
c. the acceleration due to gravity.
b. the height of the object.
d. All of the above
____ 16. The brakes on a car exert a frictional force of 6000 N in getting the car to stop. If the work done by the brakes
is 120 000 J in coming to a stop, how many meters did the car travel after the driver applied the brakes?
a. 6 m
c. 12 m
b. 20 m
d. 40 m
____ 17. The law of conservation of energy states that
a. the energy of a system can disappear.
b. it is impossible to make a perpetual motion machine.
c. energy cannot change form.
d. energy can neither be created nor destroyed.