| A | B |
|---|
| force | A push or pull exerted on an object. |
| net force | The overall force on an object when all the individual forces acting on an object are added together. |
| unbalanced forces | A nonzero net force that changes an object's motion. |
| balanced forces | Equal forces acting on an object acting in opposite directions. |
| inertia | The tendency of a moving object to continue in a straight line or a stationary object to remain in place. |
| Newton | A unit of measure that equals the force required to accelerate one kilogram of mass at a rate of one meter per second per second. |
| friction | A force that one surface exerts on another when the two rub against each other. |
| sliding friction | Friction that occurs when one solid surface slides over another. |
| rolling friction | Friction that occurs when an object rolls over a surface. |
| fluid friction | Friction that occurs as an object moves through a fluid. Air counts as a fluid. |
