| A | B |
|---|
| Force | A push or a pull |
| Newton | SI Unit of Force |
| Net Force | The sum of all forces on an object |
| Balanced Forces | Forces that cancel out (net force=0) |
| Friction | A force that opposes motion between two surfaces that are touching |
| Gravity | An attractive force between any two objects that depends on the masses of the objects and the distance between them |
| Law of Universal Gravitation | Gravitational force increases as the mass of either object increases, and the objects move closer |
| Mass | Measures the amount of matter (in kg, g, etc.) |
| Weight | Measures the gravitational force (in N) |
| Newton’s First Law of Motion | An object at rest remains at rest, an object in motion remains in motion in a straignt line at constant speed, unless either of these objects is acted upon by an unbalanced force. |
| Newton’s Second Law of Motion | F=ma |
| Newton’s Third Law of Motion | Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. |
| Air resistance | Friction-like force that opposes the motion of objects moving through air |
| Terminal Velocity | Maximum velocity for a falling object |
| Free fall | The motion of an object when gravity is the only force acting upon it (no air resistance) |
| Law of Conservation of Momentum | If no external forces act upon a group of objects, their total momentum does not change |
