| A | B |
|---|
| Force | A push or a pull on an object that can cause it to change motion |
| Gravity | A force that pulls any two objects toward one another, such as you, toward the center of the earth. |
| Inertia | The tendency of a moving object to stay in motion or a resting object to stay at rest |
| Friction | A force that slows the motion of moving objects |
| Energy | The ability to do work |
| Potential energy | Energy that an object has because of its position |
| Kinetic energy | Energy of motion |
| Mechanical energy | The kind of energy an object has because it can move or because it is moving |
| Chemical energy | Energy that comes from chemical changes |
| Electrical energy | Energy that comes from the flow of electricity |
| Work | The result of force on a moving object |
| Simple machine | A machine made of one or two parts |
| Compound machine | A machine made of two or more simple machines |
| Complex machine | A machine made of simple and compound machines |
