| A | B |
|---|
| force | push or pull that acts on an object, causing it to move, change speed or direction, or stop moving |
| gravity | the force that exists between any two objects that have mass, attracting or pulling them together |
| newton | unit of force, equal to the force that causes 1-kilogram mass to accelerate at a rate of 1 m/s/s |
| net force | force that results from the combination of all the forces that act on the object |
| balanced forces | forces that cancel each other because they are equal in strength and opposite in direction |
| Law of Conservation of Momentum | the total momentum of a group of interacting objects does not change unless an outside force acts on the objects |
| acceleration | rate at which an object's velocity changes |
| air resistance | fluid friction acting on an object moving through air; also called drag |
| mass | amount of matter in an object |
| weight | measure of the force of gravity acting on an object |
| momentum | property of matter due to its mass and velocity |
| unbalanced forces | forces that do not cancel each other out and result in a net force on an object |
