| A | B |
|---|
| work | the product of force and distance |
| power | the rate of doing work |
| horsepower | equal to about 746 watts |
| joule | the product of force and distance resulting in the units of newton-meters. The SI unit of work |
| watt | The SI unit of power |
| machine | a device that changes a force |
| input distance | the distance the input force acts through |
| output force | the force that is exerted by a machine |
| work output | the output force multiplied by the output distance |
| input force | the force you exert on a machine |
| work input | the work done by the input force acting through the input distance |
| output distance | the distance the output force is exerted through |
| mechanical advantage | the number of times that the machine increases an input force |
| actual mechanical advantage | the ratio of the output force to the input force |
| ideal mechanical advantage | the mechanical advantage in the absence of friction |
| efficiency | the percentage of work input that becomes work output |
| lever | a rigid bar that is free to move around a fixed point |
| fulcrum | the fixed point that the bar rotates around |
| input arm | the distance between the input force and the fulcrum |
| output arm | the distance between the output force and the fulcrum |
| wheel and axle | a simple machine that consists of two disks or cylinders, each one with a different radius |
| 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 in a wheel |
| compound machine | a combination of two or more simple machines that operate together |
