Lightning usually occurs as a bright zigzag flash in thunderclouds and is accompanied by thunder. Its electrical discharge reaches 100,000 amperes, and its voltage reaches several hundred million volts. To determine the distance to lightning, you need to calculate the time in seconds from the flash to the first rolls of thunder.
Necessary
- - stopwatch or watch $
- - calculator.
Instructions
Step 1
Lightning is a natural phenomenon dangerous to human life. However, ironically, it is through the fault of people that there are more and more of them. This is due to an extremely irresponsible attitude to the environment: ambient air pollution in megalopolises increases the heating of the air environment and the rise of steam-condensate into the atmosphere. This increases the electrical intensity in the clouds and provokes lightning discharges.
Step 2
The need to determine the distance to lightning is caused not only by the need to expand the horizons, but also by the elementary instinct of self-preservation. If it is too close, and you are in an open space, then it is better to run away from there as quickly as possible. The electric current chooses the shortest path to the ground, and the skin is an excellent conductor for it.
Step 3
Start counting the seconds, as soon as you see a flash of light in the sky, use your watch or stopwatch. As soon as the first clap of thunder is heard, stop counting, so you get time.
Step 4
In order to find the distance, you need to multiply the time by the speed. If the accuracy is not very important for you, then it can be taken equal to 0.33 km / s, i.e. multiply the number of seconds by 1/3. For example, according to your calculations, the time to lightning was 12 seconds, after dividing by 3 you get 4 km.
Step 5
To determine the distance to lightning more accurately, take the average speed of sound in air equal to 0, 344 km / s. Its true value depends on many factors: humidity, temperature, type of terrain (open space, forest, urban high-rise buildings, water surface), wind speed, etc. For example, in rainy autumn weather, the speed of sound is approximately 0.338 km / s, in summer dry heat, it is about 0.35 km / s.
Step 6
Dense forests and tall buildings slow the speed of sound significantly. It decreases due to the need to bend around numerous obstacles, diffraction. It is rather difficult to carry out an accurate calculation in this case, and most importantly it is impractical: despite the fact that lightning does not strike the ground, it can strike a tall tree next to you. So wait it out between low-growing trees with a dense crown, best of all, squatting, and if you find yourself on a city street, then take refuge in the next building.
Step 7
Pay attention to the wind. If it is strong enough and blows in your direction away from the lightning, then the sound is coming faster. Then its average speed can be taken approximately equal to 0, 36 km / h. When the wind is directed from you to the lightning, the movement of sound, on the contrary, slows down and the speed is approximately 0, 325 km / h.
Step 8
The average length of lightning reaches 2.5 km, and the discharge extends to a distance of up to 20 km. Therefore, you should move as quickly as possible from an open place to the nearest building or structure. Remember that when lightning approaches, you need to close all windows and doors and turn off electrical appliances, as a shock through the antenna and through the network can harm your equipment.
Step 9
Lightnings are not only ground-based, but also intra-cloud. They are not dangerous for those on the ground, but they can damage flying objects: airplanes, helicopters and other vehicles. In addition, a metal object caught in a cloud with a strong electric field capable of supporting, but not creating a charge, can initiate lightning and provoke its appearance.
