speed
the distance traveled divided by the time it took to travel: speed = distance/time
Velocity
the speed of an object in a particular direction
Acceleration
the rate at which velocity changes over time; an object accelerates if its speed, direction, or both change
Motion
an object's change in position relative to a reference point
reference point
nonmoving or moving point from which motion is measured
Force
a push or a pull exerted on an object in order to change the motion of the object; force has size and direction