Things in motion travel certain distances in given times. An automobile, for example, travels so many kilometers in an hour. Speed is a measure of how fast something is moving. It is the rate at which distance is covered,and  is always measured in terms of a unit of time. In general, Speed=distance/time.

Any combination of distance and time units is legitimate for measuring speed; for motor vehicles the units kilometers per hour or miles per hour are commonly used. For shorter distances, meters per second are often useful units.

Furthermore, speed enters as a feature or as one of the many characteristics that describe motion, therefore, we will see in coming publications other forms of speed measurements such as average speed.