calculate average speed
The average speed of an object is the total distance traveled by the object divided by the elapsed time to cover that distance. It's a scalar quantity which means it is defined only by magnitude. A related concept, average velocity, is a vector quantity. A vector quantity is defined by magnitude and direction.ommon units include miles per hour (mph), kilometers per hour (kph), meters per second (m/s), or feet per second (ft/s). As for your brand-new red sports car, your friend was exactly right in his calculation of the average speed. He used the distance traveled by the car (45 miles) divided by elapsed time (1.25 hours).