Chapter 12

Question 0

Multiple pulleys put together in a single unit

Answer 0

Block and tackle

Question 1

Which of the following is not a simple machine?

Answer 1

A pair of scissors

Question 2

A dropped racquetball will not return to it’s original position because

Answer 2

Some of the mechanical energy is converted to nontechnical energy

Question 3

The sum of an objects kinetic and potential energies

Answer 3

Mechanical energy

Question 4

A lever it pulley connected to a shaft

Answer 4

Wheel and axle

Question 5

The energy due to motion

Answer 5

Kinetic energy

Question 6

What are the units of work?

Answer 6

All of these

Question 7

An inclined plane

Answer 7

Changes both the magnitude and the direction of the force

Question 8

A ramp is a simple inclined plane the allows one to apply an input force _____ the output force

Answer 8

Less than

Question 9

A ramp is a _______ that decreases the force required to move an object while increasing the distance the object travels

Answer 9

Machine

Question 10

Which of the following statements is NOT true?

Answer 10

If the kinetic energy of an object decreases, the nonmechanical energy will decrease

Question 11

At the top of its arc, a thrown ball has _______ potential energy

Answer 11

Maximum

Question 12

Which of the following is an example of a wheel and axle?

Answer 12

A screwdriver

Question 13

An example of a second-class lever

Answer 13

Wheelbarrow

Question 14

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

Answer 14

Work

Question 15

What is the mechanical advantage of a single, fixed pulley?

Answer 15

1

Question 16

The law of conservation of energy states that

Answer 16

Energy can neither be created nor destroyed

Question 17

Gravitational potential energy depends on the

Answer 17

All of these

Question 18

Which of the following is an example of a third-class lever?

Answer 18

A hand-held boat paddle

Question 19

A boy exerts an average force if 50 N when he lifts a box 4 meters. How much work does he do?

Answer 19

200J

Question 20

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

Answer 20

Potential energy

Question 21

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

Answer 21

Nonmechanical energy

Question 22

A system that receives energy from external sources is called

Answer 22

Open

Question 23

What is the mechanical advantage of a ramp that is 16 meters long and 2 meters high?

Answer 23

8

Question 24

Levers are divided into_______ classes based o the location of the fulcrum and of the input and output forces

Answer 24

Three

Question 25

Which of the following is an example of mechanical energy?

Answer 25

Potential energy

Question 26

______ is a measure of the ability to do work

Answer 26

Energy

Question 27

A wedge is a modified

Answer 27

Inclined plane

Question 28

Which of the following is not in the inclined plane family?

Answer 28

A wheel and axle

Question 29

How much power is required to do 200 J of work in 5 S?

Answer 29

40 W

Question 30

Mechanical energy can change to nonmechanical energy as a result of

Answer 30

Air resistance and friction

Question 31

______ is defined as the rate at which work is done

Answer 31

Power

Question 32

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?

Answer 32

Zero

Question 33

Calculate the mechanical advantage of a wrench that allows you to move a bolt 0.1 M by moving the handle 0.3 M

Answer 33

3

Question 34

A pair of tweezers is

Answer 34

A compound machine made of two third-class levers

Question 35

As a dropped penny falls toward the ground ______ energy is converted to _______ energy

Answer 35

Potential, kinetic

Question 36

When a pitcher throws a softball to a catcher, the vibration of the individual atoms that make up the softball is considered ______ energy while the motion of the ball toward the catcher is considered ____ energy

Answer 36

Nonmechanical, mechanical

Question 37

What are the units of power?

Answer 37

All of these

Question 38

A man pushes a crate along a factory floor by exerting a force of 100 N. if the crate moves a distance if 8.0 M, how much work does the man perform?

Answer 38

800 J

Question 39

What are the two families of simple machines?

Answer 39

Inclined plane and lever

Question 40

An inclined plane wrapped around a cylinder

Answer 40

Screw

Question 41

Which of the following statements about work and energy is NOT true?

Answer 41

Work and energy are always equal

Question 42

The primary source of the suns energy is

Answer 42

Nuclear fusion

Question 43

A machine is a device that

Answer 43

Can multiply and change the direction of an input force

Question 44

A first-class lever has the

Answer 44

Fulcrum in the middle

Question 45

________ is the ratio of useful work output to work input

Answer 45

Efficiency

Question 46

The kind of energy associated with atomic bonds is

Answer 46

Chemical energy

Question 47

Lifting a car using a car jack is easier because it requires

Answer 47

Less force