| A | B |
|---|
| position | the location of an object |
| gravity | a non-contact force that pulls objects toward the Earth |
| force | a push or a pull |
| motion | a change in the position of an object |
| friction | a contact force that slows down or stops moving objects |
| magnetism | a non-contact force that pull objects containing iron |
| speed | the rate at which an object changes position |
| screw | an inclined plane wrapped around a center post |
| compound machine | a machine made of two or more simple machines |
| simple machine | a machine with few or no moving parts |
| wedge | a simple machine made up of two inclined planes that meet at an edge |
| pulley | a simple machine that uses a grooved wheel and a rope to raise objects |
| inclined plane | a simple machine that raises objects from a lower level to a higher level |
| work | happens when force moves an object over a distance |
| wheel and axle | a simple machine whose parts are a wheel and a post |
| lever | a bar with a point that rocks back and forth |
