| A | B |
|---|
| Motion | a change in an object's position compared to fixed ojects around it |
| Distance | the length between any two points on the path of an object |
| Speed | How fast an object's poisiton changes with time at any given moment |
| Average speed | the total distance traveled by the amount of time |
| Gravity | a force of attaraction that exists between any objects with mass |
| Unbalanced forces | Forces that do not cancel each other out when acting together on a single object |
| Mass | a measure of how hard it is to push or pull an object |
| Net force | the combined effect of all the forces acting on an object |
| Balanced forces | Forces that cancel each other out when acting together on a single object |
| Newton first law of Motion | An object's velocity can only be changed by applying a force to it. |
| Newton Second law of Motion | The acceleration of an object is related to the object's mass and to the amount of force appleid to the object. |
| velocity | the speed and direction of a moving object |
| acceleration | the change in velocity of a moving object with time |
| sliding friction | the force of friction that opposes the motion of an object |
| rolling friction | wheels and rollers are used to reduce friction |
| static friction | prevents the start of any movement between surfaces in contact |
| drag force | a force that opposes motion of an object through a liquid or gas. |
| inertia | the tendency of an object to oppose a change in motion |
| kinetic energy | the energy of a moving object |
| potental energy | the energy stored in an object or material |
| lever | a simple machine made of a rigid bar on a pivot point |
| simple machine | a machine with few moving parts, making it easier to do work |
| work | force applied to an object times the distance the object moves in the direction of force |
| momentum | the mass of an object multiplied by its velocity |
