When an object moves in a straight line at a steady speed, we can calculate its speed if we know how far it travels and how long it takes. This equation shows the relationship between speed, distance travelled, and time took: Speed is distance divided by the time taken. Speed = Distance/Time – This tells us how slow or fast an object moves. It describes distance travelled divided by the time taken to cover the distance. The speed is the time rate of change of the distance. If 'D' is the distance of an object in some time 'T', the speed is equal to, s = D/T. It has the same units as velocity.