Chapter 12

Question 1

Work

Answer 1

Work is done when force causes a change in the position or the motion of an object in the direction of the applied force.

Question 2

Power

Answer 2

Power is the rate at which work is done, how much work is done in a given amount of time

Question 3

Mechanical advantage

Answer 3

The ratio between the output force and input force

Question 4

Joule

Answer 4

1 kg m^2/s^2

Question 5

Watt

Answer 5

Amount of power required to do one joule of work in one second

Question 6

Simple machines

Answer 6

Most basic type of machines

Question 7

Compound machines

Answer 7

Combination of simple machines

Question 8

Lever

Answer 8

Have a rigid arm that turns around a fulcrum

Question 9

First class lever

Answer 9

Fulcrum in between in and output forces

Question 10

Second class lever

Answer 10

Fulcrum at one end, input force at other end

Question 11

Third class lever

Answer 11

Multiply distance rather than force

Question 12

Pulley

Answer 12

Lever family, middle point is the fulcrum, fixed pulley has a mechanical advantage of one

Question 13

Block and tackle

Answer 13

.

Question 14

Wheel and axle

Answer 14

Pulley or lever connected to a shaft

Question 15

Inclined plane

Answer 15

Ramp redirects horizontal force upward, spreads work of larger distance

Question 16

Wedge

Answer 16

Two inclined planes pushed back to back, when forced into something, it spreads force outward, causing the object to separate

Question 17

Screw

Answer 17

A inclined wrapped around a cylinder

Question 18

Potential energy

Answer 18

Energy of position, results from relative positions of objects ina system

Question 19

Kinetic energy

Answer 19

Energy an object has because it is in motion

Question 20

Mechanical energy

Answer 20

Amount of work an object can do because of the objects kinetic and potential energy

Question 21

Elastic potential energy

Answer 21

Energy stored in any type of stretched elastic material

Question 22

Gravitational potential energy

Answer 22

Energy that results from position above the ground

Question 23

Non mechanical energy

Answer 23

Energy that does not affect motion on a large scale

Question 24

Efficiency

Answer 24

How much useful work it can do

Question 25

Open system

Answer 25

Exchange energy within the space that surrounds them

Question 26

Closed system

Answer 26

When the flow of energy is small enough that it can be ignored

Question 27

Perpetual motion machines

Answer 27

Designed to keep going without input