Welcome to brain Stuff from how stuff works dot com where smart Happens. Hi, I'm Marshall Brain with today's question, how can you figure out how far away lightning struck? If you can see the bolt of lightning actually strike the ground, or if you can see a flash from a bolt of lightning, you can calculate how far away it's struck by timing the arrival of the thunder. Let me show you how to do this with miles first, and then we'll do it in kilometers. The sound of
thunder travels through the air at the speed of sound. Officially, the speed of sound is about feet per second, so sound travels one mile in roughly five seconds. When you see the flash of a lightning bolt, you can start counting seconds and then divide by five to see how far away the lightning struck. For example, if it takes ten seconds for the thunder to roll in, you divide by five and you know that the lightning struck about
two miles away. Now let's do it in metric Officially, this either sound is about three meters per second, so sound travels one kilometer in roughly three seconds. When you see the flash of a lightning bolt, you can start counting seconds and then divide by three to see how far away the lightning struck. If it takes ten seconds for the thunder to roll in, you can divide by three and you know that lightning struck about three kilometers away. Do you have any ideas or suggestions for this podcast?
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