Lightning – the huge electrospark category in the atmosphere which is usually followed by light flash and a thunder. Between flash and the heard category of a thunder there is a small delay on which duration it is possible to calculate distance to the struck lightning.
It is required to you
- Stop watch, calculator
Instruction
1. So, expect a lightning with a stop watch in a hand. At the time of flash start a stop watch when you hear a thunder, switch off a stop watch. As a result you receive thunder delay time – that is time for which fluctuation of air took place from the place of the category to you.
2. Further, the distance, on the known formula, is the work of speed of the movement for a while. You have time. As for sound in the atmosphere speed, for rough calculations 343 meters per second are enough to remember value. If you want to calculate distance more or less precisely, then it is necessary to remember that in damp air the sound extends quicker, than in dry, and in hotter – quicker, than in cold. For example, in the cold fall at a storm rain the acoustic speed in air will be 338 m/s, and in the hot and dry summer – 350 m/s.
3. Now consider. For example, from flash of a lightning to a sound of a thunder there passed 8 seconds. You take acoustic speed - 343 m/s, then the distance till the lightning will be 8 * 343 = 2744 meters, or (rounding) 2.7 kilometers. If air temperature the 15th rain of average force), then acoustic speed is 341.2 m/s, and distance of 2729.6 m (it is possible to round to 2.73 km).
4. You can enter admission on the direction of wind. If wind blows in the direction from a lightning to you, the sound will pass this distance slightly quicker, and at the direction of wind from you by a lightning – slightly more slowly. For rough calculations it is enough to remember that in the first case (wind by a lightning) distance needs to be reduced by 5%, and in the second (wind from a lightning) to increase by 5%. Thus, at a thunder delay 8 sec. and the acoustic speed of 343 m/s at the direction of wind from a lightning to you the distance 2744 meters should be increased by 137.2 m.