You can estimate the distance of a thunderstorm in kilometers by counting the number of seconds between the lighting flash and the thunder and then dividing the number by 3. If a storm in 5km away how many seconds will you count between the lighting flash and the thunder?
If the distance is equal to the counted number of seconds divided by 3, then multiply the distance by 3 to determine the number of counted seconds . . (5 km)(3) = 15 seconds counted between lightning and thunder.
