| Term | Definition |
| terminal velocity | the constant velocity of a falling object when the size of the upward force of air resistance matches the size of the downward force of gravity |
| free fall | the condition an object is in when gravity is the only force acting on it. |
| projectile motion | the curved path an object follows when thrown or propelled near the surface of the earth. |
| inertia | the tendency of all objects to resist any change in motion |
| momentum | a property of a moving object that depends on the object's mass and velocity |