| A | B |
|---|
| force | a push or pull acting on an object |
| newton | the SI unit of force |
| net force | the overall force acting on an object |
| balanced force | when forces are equal |
| unbalanced force | when forces are unequal |
| friction | force that opposes motion between two surfaces that are touching each other |
| static friction | force between two surfaces that are not moving past each other |
| sliding friction | force that opposes the motion of two surfaces sliding past each other |
| rolling friction | force between a rolling object and the surface it rolls on |
| fluid friction | force that acts on objects that are moving through a fluid |
| fluid | a substance that can flow and take the shape of its container |
| inertia | the tendency of an object to resist any change in its motion |
| Newton's 1st Law | an object in motion stays in motion and an object at rest stays at rest unless acted upon by an outside unbalanced force |
| Newton's 2nd Law | the acceleration of an object is in the same direction as the net force on the object |
| Newton's 3rd Law | every action has an equal and opposite reaction |
| terminal velocity | the highest speed a falling object will reach |
| centripetal force | the net force exerted toward the center of a curved path |
| weight | measures the force of gravity pulling on an object |
| momentum | a property of a moving object that makes the object hard to stop |
| air resistance | fluid pressure with the air |
