| A | B |
| gravitation | The force that pulls all objects in the universe toward one another. |
| magnetism | The force of pushing or pulling between poles of magnets. |
| balanced forces | The forces acting on an object that are equal in size and opposite in direction, canceling each other out. |
| net force | The result of two or more forces acting together on an object. |
| unbalanced forces | Forces that are not equal. |
| machine | Something that makes work seem easier by changing the size or the direction of a force. |
| power | The amount of work done for each unit of time. |
| work | The use of a force to move an object through a distance. |
| acceleration | A change of motion caused by unbalanced forces or a change in velocity. |