| A | B |
|---|
| Motion | an object's change in position over time when compared with a reference point |
| Reference Point | an object that appears to stay in place in relation to an object being observed for motion. |
| Speed | the rate at which an object moves; depends on the distance traveled and the time taken to travel that distance |
| Velocity | the speed of an object in a particular direction |
| Acceleration | the rate at which velocity changes, occurs when speed and direction change. |
| Positive Acceleration | acceleration in which velocity increases |
| Negative Acceleration | Acceleration in which velocity decreases. |
| Force | a push or a pull, all forces have both size and direction |
| Newton | S I unit for measuring force |
| Net Force | is the force that results from combining all the forces exerted on an object |
| Unbalanced Force | when the net force on an object is not zero, produced a change in motion |
| Balanced | when the force applied to an object produce a net force of zero |
| Friction | is a force that opposes motion between two surfaces that are touching. |
| Lubricants | are substances that are applied to surfaces to reduce the friction between them. |
| Gravity | is a force of attraction between objects that is due to their masses. |
| Mass | the amount of matter that something is made of; its value does not change with the object's location in the universe. |
| Weight | a measure of the gravitational force exerted on an object, usually by the Earth. |
| Inertia | is the tendency of an object to resist the change in its motion. |
| Sliding Friction | when solid surfaces slide over each other |
| Rolling Friction | when an object rolls over a surface. |
