| A | B |
|---|
| force | push or pull |
| net force | the overall force on an object after all the forces are added together |
| unbalanced forces | forces that combine to produce a net force which causes a change of motion |
| balanced forces | equal forces actiong in opposite directions on an object |
| inertia | resistance to change in motion |
| newton | force required to accelerate one kilogram of mass at one meter per second per second |
| friction | firce that one surface exerts on another when they rub against each other |
| sliding friction | friction that occurs when two surfaces slide over each other |
| rolling friction | friction that occurs when an object rolls over a surface |
| fluid friction | friction that occurs when an object moves through a liquid or a gass |
| gravity | force that pulls things towards the center of Earth |
| free fall | when gravity is the only force acting on a falling object |
| projectile | a thrown object |
| air resistance | fluid friction experienced by objects falling through air |
| terminal velocity | the maximum velocity a falling object achieves |
| law of conservation of momentum | total momentum of objects that interact does not change |
| law of universal gravitation | gravity acts between all objects in the universe |
| momentum | product of an object's mass and velocity |
| satellite | any object that travels around another object |
| centripetal force | force that causes an object to move in a circle |
