Use the speed of sound to calculate the distance of a storm cloud from your location.
A storm usually brings with it plenty of lightning and thunder. If you have a stopwatch and a calculator, you can use the time delay between the flash of lightning and its accompanying thunderclap to calculate the distance of the storm with remarkable precision. Since the light from a lightning flash reaches you almost instantaneously (light travels over 185,000 miles per second), all you need to know is the speed of sound and the time it took the sound to reach your ears to determine the distance to the thunder cloud.
Instructions
1. Wait for a lightning flash to appear in the storm. Start your stopwatch the instant you see one.
2. Listen carefully for the thunderclap. Stop the stopwatch as soon as you hear it.
3. Convert the time between lightning flash and thunderclap from seconds to hours by dividing the seconds on the stopwatch by 3600 (the number of seconds in an hour) on your calculator. For example, if you counted 10 seconds between lightning and thunder, you would divide 10 by 3600 to get 0.00278.
4. Multiply the resulting number by 750 to determine the distance in miles to the storm cloud. The speed of sound at the altitude of storm clouds is about 750 miles per hour. The formula distance = rate x time tells you that multiplying the speed of sound by the time it took the sound to arrive gives you the distance to the source of the sound (in this case, the storm cloud where the lightning originated). If the time difference was 10 seconds, multiply 0.00278 by 750 to get the distance: 2.08 miles.
Tags: speed sound, lightning flash, storm cloud, between lightning, calculate distance
