Let us discuss the definitions of speed, uniform speed, variable speed, average speed and instantaneous speed in the following section:

**1. Speed:** The time rate of change of position of a body in any direction is known as its speed.

It is measured by the ratio of the distance by a body to the time in which this distance is covered

i.e. Speed = distance/time

Speed is a scalar quantity. It is either positive or zero but never negative.

Units of speed: We know that,

Speed = Distance/Time

Units of speed = Units of distance/Units of time

In the CGS system, unit of speed is cms^{-1} and in the MKS system or SI units the unit of speed is ms^{-1}. Continue reading “Speed, Uniform speed, Variable speed, average speed, Instantaneous speed”