# Science Chapter 4: Work and Machines Vocabulary

## 14 terms · A overview of chapter four vocabulary

### Efficiency

The percentage of the input work that is converted to output work

### Fulcrum

the fixed point around which a lever pivots

### Inclined Plane

a flat surface with one end higher than the other

### Input Force

the force exerted on a machine

### Output Force

the force exerted on an object by a machine

### Joule

a unit of work equal to one Newton-meter

### Lever

a simple machine that gives a mechanical advantage when given a fulcrum

### Machine

a device that changes the amount of force exerted or the direction in which force is exerted

the number of times the force exerted on a machine is multiplied by the machine

### Pulley

A grooved wheel around which is wrapped a rope, chain, or cable

### Screw

an inclined plane wrapped in a spiral around a cylindrical post

### Wedge

an inclined plane that moves

### Wheel and Axle

a simple machine made of two circular or cylindrical objects fastened together that rotate about a common axis.

### Work

force exerted on an object that causes it to move