| A | B |
|---|
| air resistance | force that opposes the motion of objects that move through the air |
| friction | force that opposes the sliding motion between two touching surfaces |
| Newton's second law of motion | states that the acceleration of an object is in the same direction as the net force on the object, and that the acceleration equals the net force divided by the mass |
| sliding friction | frictional force that opposes the motion of two surfaces sliding past each other |
| static friction | frictional force that prevents two surfaces from sliding past each other |
| terminal velocity | the highest speed a falling object will reach |
| centripetal acceleration | acceleration of an object toward the center of a curved or circular path |
| centripetal force | a net force that is directed toward the center of a curved or circular path |
| gravity | attractive force between two objects that depends on the masses of the objects and the distance between them |
| weight | gravitational force exerted on an object, measured in Newtons (N) |
| mass | the amount of matter in an object, measured in grams (g) or kilograms (kg) |
| projectile | anything that's thrown or shot through the air |
| momentum | property of a moving object that equals its mass times its velocity |
| Newton's third law of motion | states that when one object exerts a force on a second object, the second object exers a force on the first object that is equal in strength and in the opposite direction. |
| Law of Conservation of Momentum | If a group of objects exerts forces only on each other, their total momentum is the same before and after their collision |
