| A | B |
|---|
| force | a push or pull |
| net force | combination of all forces acting on an object |
| balanced forces | two or more forces whose effects cancel each other out and do not change the motion of an object |
| unbalanced forces | two or more forces acting on an object that do not cancel, causing the object to accelerate |
| Newton's first law of motion | an object at rest will remain at rest and an object in motion will remain in motion unless acted upon by an outside force |
| friction | force that acts to oppose sliding between two surfaces that are touching |
| Newton's second law of motion | an object acted upon by a net force will accelerate in that directon of force F = ma |
| weight | gravitational force between an object and Earth |
| center of mass | point in an object that moves as if all of the object's mass were concentrated at that point |
| Newton's third law of motion | forces always act in equal but opposite pairs |
| static friction | prevents an object from moving when a force is applied-HEAVY |
| sliding friction | slows down an object that slides |
| rolling friction | occurs when an object rolls across a surface |
| Newton | SI unit for force |
| kg | SI unit for mass |
| m/s2 | SI unit for acceleration |
| gravity | force that is attractive and pulls objects towards each other |
| centripetal force | when an object moves in a circular motion, the net force on the object |
| air resistance | a form of friction that acts to slow down any object moving in air |
| free fall | occurs when the only force acting on an object is gravity |
