Velocity is defined as the derivative of position with respect to time,

(1)

For one-dimensional motion,

(2)

(3)

Conversions between common units of velocity include 1 mi h^-1 = 0.447 m s^-1and 1 km h^-1 = 0.278 m s^-1.

In terms of the angular velocity ,

In magnitude,

(4)

These equations hold only for , where c is the speed of light. For relativistic motion,

			(5)

			(6)
			(7)

(8)

Admiralty Knot, Group Velocity, Knot, Maxwell Distribution, Sound, Velocity Four-Vector, Wave Velocity