How can you measure how fast something is moving? You can do it quite easily with a meter stick and a stopwatch. Meter sticks measure distance and stopwatches measure time. How can that information be useful?
Speed is a measure of how fast something is moving. For example a car may have a speed of 40mph or 60m/s. The units mph (miles per hour) and m/s (meters per second) hint toward the answer to our question. The units show that to obtain a speed, you must divide the distance traveled by the time it took to travel this distance. Simple as that!