How does counting the seconds between lightning and the thunder in tell ing how far away lightning is, work?

Answer 1

Just to confirm the answers from two of the others... the speed of sound decreases from 761 - 707 MPH between 0 - 20,000 feet (Speed is greater at lower altitudes due to higher air density.)

So 750 MPH is a pretty decent number to use, and with 5,280 feet per mile:

750 x 5,280 = 3,960,000 (feet per hour)
3,960,000 / 60 = 66,000 (feet per minute)
66,000 / 60 = 1,100 (feet per second)

Therefore sound takes approximately 5 seconds to travel one mile. Not 1 second for each mile. Counting to 10 would equal TWO miles, not TEN miles as another stated.

Answer 2

When you see lightning, count 1000-1, 1000-2, 1000-3 so on and so forth and when you hear the thunder, the total seconds counted is the equivalent distance in miles.

For example, at the strike of lightning you counted 1000-1, 1000-2 etc., and at 10 you heard thunder that means the lightning stroke an area 10 miles from where you stand.

Answer 3

Here is how it works:

Lightning and thunder are generated at the same time. The lightning is seen, so it travels at the speed of light (the image of the lightning), the thunder is sound so it travels at the speed of sound. By taking the difference between how long it takes the light to reach you and the sound to reach you, the distance can be approximated.

For the calculation itself, the speed of light can be considered instant (using the actual value would have no noticable effect on the result). The speed of sound is a little over 1000ft/second. 1mile = 5,285 feet so that for every 5 seconds you count, the sound has traveled approximately 1 mile.

Answer 4

In simple terms (!), the shorter the time between when you hear the thunder and see lightning in the sky, the closer the lightning is. If you hear thunder and see lightning half a minute later, it's farther away than if you see and hear it together (when it would be right above you). How fast the wind is blowing, and in what direction, will help you determine when and if you should take cover.

Answer 5

for each 5 seconds between the time you spot the flash of lightening and the sound of thunder, the typhoon (lightening) is a million mile away. to illustrate, in case you count quantity off 15 seconds till you right here the thunder the lightening is 15/5=3 miles away.

Answer 6

By counting the seconds between the lightning and thunder and dividing by three, we get the distance of the storm in Kilometres and dividing by five, we get the distance in Miles.

Answer 7

The flash comes in at the speed of light, the thunder at the speed of sound.

Speed of light = 186,000 miles per second.

Speed of sound = 750 miles per hour or about 5 seconds to travel 1 mile.

So if the thunder takes 5 seconds to reach you, it was about a mile away.

Answer 8

every 5 seconds is equivalent to 1 mile