| Term | Definition |
|---|---|
| Unbalanced force | a set of forces exerted on an object that change the motion of that object; the combined force has size and direction |
| Speed | a measure of how fast something moves; rate of motion |
| Direction | the path that something takes, the path that must be taken to reach a specific place, the way in which something is starting to develop or the way you are facing. |
| Motion | an object's change in position relative to a reference point |
| Force | a push or pull exerted on an object; force has size and direction |
| Acceleration | the rate at which velocity changes over time; an object accelerates if its speed, direction, or both change |
| Mass | is a property of a physical system or body, giving rise to the phenomena of the body's resistance to being accelerated by a force and the strength of its mutual gravitational attraction with other bodies |
| Net force | the combination of all of the forces acting on an object |
| Constant speed | object will cover the same distance every regular interval of time. |
| Newton | the SI unit for force |
| Friction | a force that opposes motion between two surfaces that are in contact |
| Frictionless | not impeded by or creating friction; smooth. |
