| A | B |
|---|
| Force | A push or a pull. |
| Balanced Forces | Equal forces acting on one object. |
| Unbalanced Forces | Unequal forces acting on one object. |
| Inertia | The tendency of an object to resist a change in motion. |
| Mass | The amount of matter in an object. |
| Weight | The measure of the downward pull of gravity. |
| Newton's First Law of Motion | An object at rest stays at rest and an object in motion at a constant speed stays in motion at a constant speed unless acted upon by an unbalanced force. |
| The Law of Inertia | Another name for Newton's First Law. |
| Newton's Second Law of Motion | The amount of force needed to move an object depends on the mass of the object and how you want to accelerate it. |
| F= m x a | The equation used to show the relationship among the quantities of Newton's Second Law. |
| Gravity | A downward pulling force. |
| Acceleration of Gravity | The rate at which the gravity of Earth causes all falling objects to to speed up every second they fall. (9.8 m/s/s) |
| Mass of an object and the distance between two objects | The quantities that affect the strenght of the pull of gravity. |
| Friction | A force that occurs when 2 surfaces rub together. |
| Type of surface and how hard the surfaces push together. | The quantities that affect the strength of the force of friction. |
| Air Resistance | A friction caused when objects move through air molecules |
| 3 Kinds of Friction | Sliding, Rolling, Fluid |
| Free Fall | When the only force acting on an object is gravity. |
| Terminal Velocity | The greatest velocity a falling object reaches. |
| Universal Law of Gravity | The force of gravity acts between all objects in the universe. |
