| A | B |
|---|
| speed | A measure of how far something travels in a certain period of time. |
| velocity | A measure of speed in a certain direction. |
| inertia | The tendency of an object to stay at rest or to remain in motion unless an outside force causes a change. |
| gravity | A force that acts to pull pairs of objects together. |
| mass | The amount of matter in an object. |
| acceleration | Rate of change in speed or direction of movement. |
| weight | The force gravity exerts on an object's mass. |
| friction | A force that resists the movement of one surface past another surface. |
| Newton's First Law | An object will stay at rest or move at a constant speed in a straight line unless acted upon by an unbalanced force. |
| Newton's Second Law | The rate of change of the momentum of a body is directly proportional to the net force acting on it, and the direction of the change in momentum takes place in the direction of the net force. |
| Newton's Third Law | To every action (force applied) there is an equal but opposite reaction (equal force applied in the opposite direction). |
