| A | B |
|---|
| Force | A push or pull that one object exerts on another |
| Newton | SI unit of force |
| Net Force | Combined forces (when two or more forces act on an object) |
| Balanced Forces | Forces on an object that are equal in size and opposite in direction (net force of zero) |
| Unbalanced Forces | When forces combine to produce a net force that is not zero |
| Friction | The force that opposes the sliding motion of two surfaces that are in contact |
| Microwelds | The bumps and dips that touch each other between two surfaces |
| Static Friction | The frictional force that prevents two surfaces in contact from sliding past each other |
| Sliding Friction | The force that acts in the opposite direction to the motion of a surface sliding on another surface |
| Rolling Frction | When an object rolls over a surface, this is the fricitonal force |
| Air Resistance | A type of frictional force that opposes the motion of objects that move through the air |
| Terminal Velocity | When a falling object reaches a steady velocity because the force of gravity and air resistance are equal |
