Chapter 20

Question 0

Work

Answer 0

Is done when a force exerted on an object causes that object to move the same distance; equal to force times distance; measured in joules (J)

Question 1

Power

Answer 1

Rate at which work is done; equal to the work done divided by the time it takes to do the work; measured in watts

Question 2

Input force

Answer 2

Force exerted on a machine

Question 3

Output Force

Answer 3

Force exerted by a machine

Question 4

Mechanical advantage

Answer 4

Number of times the input force is multiplied by a machine; equal to the output force divided by the input force

Question 5

Efficiency

Answer 5

Equals the output work divided by the input work; expressed as a percentage

Question 6

Simple machine

Answer 6

A machine that does work with only one movement; includes the inclined plane, wedge, screw, lever, wheel and axle, and pulley

Question 7

Compound machine

Answer 7

Machine made up of a combination of two or more simple machines

Question 8

Inclined plane

Answer 8

Simple machine that is a flat surface, sloped surface, or a ramp

Question 9

Wedge

Answer 9

Simple machine consisting of an inclined plane that moves; can have one or two sloping slides

Question 10

Screw

Answer 10

Simple machine that is an inclined plane wrapped around a cylinder or post

Question 11

Lever

Answer 11

Simple machine consisting of a rigid rod or plank that pivots or rotates about a fixed point called the fulcrum

Question 12

Wheel and axle

Answer 12

Simple machine made from two circular objects of different sizes that are attached and rotate together

Question 13

Pulley

Answer 13

Simple machine made from a grooved wheel with a rope or cable wrapped around the groove