| A | B |
|---|
| mass | amount of matter in an object |
| weight | amount of gravitational force on an object |
| gravity | attractive force between all matter |
| Sir Isaac Newton | Scientist who defined gravity and the laws of motion in the 1600's. |
| acceleration | a change in speed and/or direction |
| force | a push or a pull, can be balanced or unbalanced. |
| net force | sum of all forces acting on an object |
| velocity | speed and direction |
| balanced forces | net force of 0 Newtons, cause no change in motion |
| unbalanced forces | can cause a change in motion |
| Newton | metric (SI) measure of force or weight (N) |
| friction | a force that opposes motion |
| contact forces | forces that only act when one object touches another; for ex: a push, or friction |
| speed | distance/time -- in cm/s, m/s, or km.h |
| kinetic energy | energy of motion (a falling bungee jumper has a lot of kinetic energy) |
| potential energy | stored energy (the bungee jumper has potential energy before she jumps) |
| inertia | resistance of an object to a changes in motion (increases with mass) |
| normal force | the force that a surface exerts on an object that is pressing on it |
| Newton's first law | objects at rest tend to stay at rest and objects in motion tend to stay in motion unless acted upon by an unbalanced force |
| Newton's second law | the acceleration of an object depends on its mass and the size of the force applied; A=f/m |
| Newton's third law | "action/reaction" -- when object A exerts a force on object B; object B exerts and equal and opposite force back on object A. |
