Speed = Distance / Time

Unit:

* Distance: meters (m), kilometers (km), miles (mi), etc.

* Time: seconds (s), minutes (min), hours (h), etc.

Therefore, the unit of speed is:

* meters per second (m/s)

* kilometers per hour (km/h)

* miles per hour (mph)

Example:

If a car travels 100 kilometers in 2 hours, its speed is:

Speed = 100 km / 2 h = 50 km/h