| A | B |
|---|
| Static friction | Friction acts on objects that are not moving |
| Sliding friction | Friction when two solid surfaces slide against each other |
| Rolling friction | Friction when an object rolls across a surface |
| Fluid friction | Friction when a solid object moves through fluid |
| Air resistance | Friction that slows a falling object |
| Free fall | The state that exists when the only force acting on an object is gravity |
| Terminal velocity | A falling object reaches this when forces of gravity & air resistance are balanced |
| Projectile | An object that is thrown |
| Force | A push or a pull |
| Balanced force | Force that will not change an object’s motion |
| Unbalanced force | Force that can change an object’s motion |
| Net force | The sum of all forces acting on an object |
| Fluid friction | A surfboard goung through water displays which type of friction? |
| Static friction | Pushing desk across the floor displays which type of friction? |
| Sliding Friction | Ballet shoes against floor displays which type of friction? |
| Rolling Friction | A wheel turning on a surface displays which type of friction? |
| Gravity | The force that accelerates objects toward Earth |
| Inertia | The tendency of an object to resist a change in motion |
| Momentum | Mass X velocity |
| Mass | The amount of matter in an object |
| Weight | Measure of the force of gravity on an object |
| Newton | The SI unit for force |
| Law of Conservation of Momentum | The total momentum of objects remains the same, or is conserved, unless outside forces act on the objects |
| Newton’s 3rd Law of Motion | For every action there is an equal & opposite reaction |
