Name:    Chapter 13 -- Concepts (Few calculations)

Multiple Choice
Identify the choice that best completes the statement or answers the question.

1.

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.

2.

A wheelbarrow is an example of a
 a. first-class lever. c. third-class lever. b. second-class lever. d. fourth-class lever.

3.

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

4.

What is the mechanical advantage of a single movable pulley?
 a. 1 b. 1.5 c. 2 d. 3

5.

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.

6.

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

7.

_____ is defined as the rate at which work is done.
 a. Power b. Joule c. Speed d. Mechanical advantage

8.

A ramp is a _____ that decreases the force required to move an object while increasing the distance the object travels.
 a. force b. load c. newton d. machine

9.

Lifting a car using a car jack is easier because it requires
 a. less force. b. less work. c. less time. d. None of the above

10.

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

11.

Levers are divided into _____ classes based on the location of the fulcrum and of the input and output forces.
 a. two b. three c. four d. five

12.

A wedge is a modified
 a. wheel and axle. c. inclined plane. b. pulley. d. lever.

13.

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

14.

Which of the following is an example of a compound machine?
 a. scissors c. wheel and axle b. ax blade d. screw

15.

What is the mechanical advantage of a single, fixed pulley?
 a. 0.5 b. 1 c. 2 d. 4

16.

_____ is a measure of the ability to do work.
 a. Photosynthesis b. Power c. Respiration d. Energy

17.

At the top of its arc, a thrown ball has _____ potential energy.
 a. maximum b. minimum c. zero d. average

18.

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

19.

 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.

20.

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.

21.

_____ is the ratio of useful work output to work input.
 a. Potential energy c. Kinetic energy b. Efficiency d. Power

22.

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?
 a. 200 N c. zero b. 200 L d. None of the above

23.

What are the units of work?
 a. J c. kg • m2/s2 b. N • m d. All of the above

24.

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.

25.

What is the mechanical advantage of a single, fixed pulley?
 a. 1 b. 1.5 c. 2 d. 3

26.

An inclined plane
 a. changes the direction of the force only. b. changes the magnitude of the force only. c. changes both the magnitude and the direction of the force. d. decreases the amount of work done.

27.

Which of the following is a compound machine?
 a. a wheel and axle c. a pair of scissors b. a pulley d. a ramp

28.

The primary source of the sun’s energy is
 a. chemical energy. c. nuclear fission. b. nuclear fusion. d. potential energy.

29.

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.

30.

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?
 a. 165 N b. 220 N c. zero d. 145 J

31.

What are the units of power?
 a. watts c. joules per second b. horsepower d. All of the above

32.

Which of the following is not a simple machine?
 a. a lever c. a screw b. a pair of scissors d. a wheel and axle

33.

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

34.

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

35.

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.

36.

Gravitational potential energy depends on
 a. the mass of the object. c. the acceleration due to gravity. b. the height of the object. d. All of the above

Matching

Match each item with the correct statement below.
 a. block and tackle c. wheel and axle b. wheelbarrow d. screw

37.

a lever or pulley connected to a shaft

38.

an example of a second-class lever

39.

an inclined plane wrapped around a cylinder

40.

multiple pulleys put together in a single unit

Match each item with the correct statement below.
 a. potential energy c. kinetic energy b. nonmechanical energy d. mechanical energy

41.

the sum of an object’s kinetic and potential energies

42.

the energy due to motion

43.

the energy of an object due to its position, shape, or condition

44.

energy that lies at the level of atoms and that does not affect motion on a large scale