Measuring speed requires time (T) and a known distance (D). Using the formula distance = rate x time (D=R*T), one determines the average speed by dividing distance by time, or R = D/T. This method assumes the object being measured is already in motion.Continue Reading
Time units are always in hours, minutes or seconds. Distance units can be either metric or imperial.
Select two points, A and B, to represent the known distance. It should be long enough to make an accurate time measurement. The shorter the distance, the more precise the time measurement must be.
As the object passes point A, start measuring the time. Using second hands on a watch or stopwatch increases accuracy when using shorter distances.
Note the elapsed time the object took to travel between the two points.
Using the formula R = D/T, determine the average rate of speed. This is usually expressed as distance per time unit.