| A | B |
|---|
| force | a push or pull |
| gravity | the force that makes objects pull toward each other |
| friction | the force caused by two objects rubbing together that slows sown or stops objects |
| work | something done whenever a force makes an object move a distance |
| energy | the ability to do work |
| simple machine | one of six kinds of tools with few or no moving parts that make work easier |
| lever | a simple machine made of a bar that is supported underneath: point |
| load | an object that is being moved |
| inclined plane | a simple machine that is a flat surface with one end higher than the other |
| wedge | a simple machine used to cut or split an object |
| screw | a simple machine that used to hold objects together |
| wheel and axle | a simple machine that has a center rod attached to a wheel |
| gear | a wheel with jagged edges like teeth |
| pulley | a simple machine made of a wheel and rope |
| compound machine | a machine that is made up of two or more simple machines |
