| A | B |
|---|
| compound machine | machine made up of a combination of two or more simple machines |
| efficiency | equals the output work divided by the input work; expressed as a percentage |
| inclined plane | simple machine that is a flat surface, sloped surface, or ramp |
| input force | force exerted on a machine |
| lever | simple machine consisting of a rigid rod or plank that pivots or rotates about a fixed point called the fulcrum |
| mechanical advantage | number of times the input force is multiplied by a machine; euqal to the outpout force divided by the input force |
| output force | force exerted by a machine |
| power | rate at which work is done; equal to the work done divided by the time it takes to do the work |
| pulley | simple machine made from a grooved wheel with a rope or cable wrapped around the groove |
| screw | simple machine that is an inclined plane wrapped around a cylinder or post |
| simple machine | machine that does work with only one movement |
| wedge | simple machine consisting of an inclined plane that moves; can have one or two sloping sides |
| wheel and axle | simple machine made from two circular objects of different sizes that are attached and rotate together |
| work | is done when a force exerted on an object causes that object to move some distance |
| joule | SI unit of work (force x distance) |
| watt | SI unit of power (1 joule per second) |
| horsepower | equals about 746 watts |
| machine | a device that changes a force |
| input distance | distance the input force acts through |
| input force | force you exert on a machine |
| output force | force exerted by a machine |
| output distance | distance the output force is exerted through |
| work output | work done by input force acting through the input distance |
| mechanical advantage | number of times that the machine increases an input force |
| actual mechanical advantage | equals the ratio of the output force to the input force |
| ideal mechanical advantage | mechanical advantage in the absence of friction |
| efficiency | percentage of the work input that becomes work output |
| flucrum | fixed point the lever rotates around |
| input arm | distance between the input force and the fulcrum |
| output arm | distance between the output force and the fulcrum |
