# Work, Power,and Machines

## 24 terms

### Work

The product of foce and distance.

### Joule

The SI unit of work.

### Power

The rate of doing work.

### Horsepower

Equal to 746 watts.

### Machine

A device that changes a force.

### Input force

The force exerted on a machine.

### Input Distance

The distance the input force acts through.

### Work Input

The work done by the input force acting through the input distance.

### Output Force

The force that is exerted by a machine.

### Output Distance

The distance the output force is exerted through.

### Work Output

The output force multiplied by the output distance.

The number of times that the machine increases an input force.

(AMA) Equals the ratio of the output force to the input force.

(IMA) The mechanical advantage in the absence of friction.

### Effiency

The percentage of work inout that becomes work output.

### Lever

A rigid bar that is free to move around a fixed point.

### Fulcrum

The fixed point the bar rotates around.

### Input Arm

The distance between the inout force and the fulcrum.

### Output Arm

The distance between the output force and the fulcrum.

### Inclined Plane

A slanted surface along which a force moves an object to a different elevation.

### Wedge

A V-shaped object whose sides are two inclined planes sloped toward each other.

### Screw

An inclined plane wrapped around a cylinder.

### Pulley

A simple machine that consists of a rope that fits into a groove into a wheel.

### Compound Machine

A combination of two or more simple machines that operate together.