| A | B |
|---|
| Force | A push or a pull |
| Net force | Combination of all forces acting on an object |
| Balanced forces | Two or more forces whose effects cancel each other and do not change the motion of an object |
| Unbalanced forces | Two or more forces acting on an object that do not cancel, and cause the object to accelerate |
| Newton's First Law | If the net force acting on an object is zero, the object will remain at rest or move in a straight line with a constant speed |
| Friction | Force that acts to oppose sliding between two surfaces that are touching |
| Newton's Second Law | An object acted upon by a net force will accelerate in the direction of the force, and that the acceleration equals the net force divided by the obejct's mass |
| 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 | Forces always act in equal but opposite pairs |
