Velocity is a measure of how fast something moves in a particular direction. In other words, a velocity is a speed with a direction. For instance, if an object moves east at 9 metres per second (9m/s), we would say that its velocity is 9 m/s to the east.
To calculate the velocity of an object, we divide its displacement (its change of position) by the time it took to change position.
For example, if an object moves 20 meters (m) to the left in 1 seconds (s), its velocity (v) would be equal to:
A change in velocity is acceleration.