Speed vs Velocity

Velocity is a vector that quantifies the rate at which an object changes its position over time. Therefore, both the magnitude and the direction of the rate are required to define the velocity of an object. Speed is the magnitude of velocity and accounts only for how fast that object is, without regard to its direction. Since it doesn't have a direction, speed is a scalar quantity.

The formula for mean velocity is:

velocity = variation of position / divided by variation of time