Chapter 12- Vocab

Question 1

Work

Answer 1

Work is 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.

Question 2

Power

Answer 2

A quantity that measures the rate at which work is done or energy is transferred.

Question 3

Mechanical advantage

Answer 3

A quantity that measures how much a machine multiplies force or distance.

Question 4

Joule

Answer 4

The label for work

Question 5

Watt

Answer 5

The SI unit for power

Question 6

Simple machines

Answer 6

One of the six basic types of machines, which are the basis for all other forms of machines.

Question 7

Compound machines

Answer 7

A machine made of more than one simple machine.

Question 8

Lever

Answer 8

Levers have a rigid arm and a fulcrum. Levers are divided into three classes: first class, second class, and third class levers

Question 9

First class lever

Answer 9

All first class levers have a fulcrum located between the points of application of the input and output forces.

Question 10

Second class lever

Answer 10

The fulcrum is at one end of the arm and the input force is applied to the other end.

Question 11

Third class lever

Answer 11

Multiply distance rather than force. As a result, they have a mechanical advantage of less than 1.

Question 12

Pulley

Answer 12

Pulleys are modified levers.

Question 13

Wheel and axle

Answer 13

Is a lever or pulley connected to a shaft

Question 14

Inclined plane

Answer 14

Multiply and redirect force. An inclined plane turns a small input force into a large output force by spreading the work put over a large distance.

Question 15

Wedge

Answer 15

A modified inclined plane. A wedge functions like two inclined planes back to back.

Question 16

Screw

Answer 16

A screw is an inclined plane wrapped around a cylinder.

Question 17

Potential energy

Answer 17

The energy that an object has because of the position, shape, or condition of the object.

Question 18

Kinetic energy

Answer 18

The energy of a moving object due to the object’s motion.

Question 19

Mechanical energy

Answer 19

The amount of work an object can do because of the object’s kinetic and potential energies.

Question 20

Elastic potential energy

Answer 20

The energy stored in any type of stretched or compressed elastic material, such as a spring or bungee cord.

Question 21

Gravitational potential energy

Answer 21

The energy that could potentially do work results from its position above the ground is called gravitational potential energy.

Question 22

Nonmechanical energy

Answer 22

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

Question 23

Efficiency

Answer 23

Effiecency is the ratio of useful work out to work in. Efficiency is usually expressed as a percentage. The efficiency of a machine is a measure of how much useful work it can do.

Question 24

Open system

Answer 24

Open system exchange energy with the space that surrounds them.most systems are open systems.

Question 25

Closed system

Answer 25

When the flow of energy into and out of a system is small enough that it can be ignored, the system is called a closed system.

Question 26

Perpetual motion machine

Answer 26

A machine designed to keep on going forever without any input of energy. These theoretical machines are called perpetual motion machines.

Question 27

Block and tackle

Answer 27

Multiple pulleys put together in a single unit.