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The thunder issunetul produced following a process of descărcare electrică in the atmosferă (fulger or trăsnet).
At the time of electric discharge, 90% of the discharged energy is rapidly transformed into heat that rapidly heats the air around the channel, with temperatures reaching up to 39,000 ° C in the case of high-intensity positive lightning . A rapid and sudden rise in pressure and temperature forces the surrounding air to expand rapidly and violently in a high-intensity shock wave , similar to a sonic boom . The shock wave spreads rapidly over a maximum distance of 10 meters, after which it slows down and becomes a sound wave perceived by our ears as thunder. In other words, thunder is air that explodes along the entire lightning channel.
The speed of sound is equal to the square root of temperature. The temperature usually decreases with altitude, unless there is a named processinversie, ie hot air passes over cold air. In this case, the thunder will be deflected upwards. Humidity, wind speed, temperature inversion, geographical properties (terrain) and clouds can affect the distance a thunder can be heard. The auditory intensity of thunder can be expressed indecibeli(dB), and is equal to 120 dB at close range. In other words, the sound produced is 10 times noisier than a garbage truck or aciocan pneumatic. In comparison, if you sit in front of the speakers at a rock concert you will be constantly exposed to the same level of dB.
Thunder is responsible for material damage when it comes to lightning. Trăsnetul represents the electric discharge but unda de șoc but the shock wavecaused by the rapid explosion of air (thunder) is responsible for material damage to buildings, poles, trees, etc. So, if a house or another building is struck by lightning, it has a high chance of being materially affected because the shock wave in the vicinity is very devastating.
Short-range thunder can also cause temporary or permanent hearing loss to the observer by puncturing the membrane. timpanului membrane .
Thunder contains a kind of initial cylindrical pressure in the form of a shock wave along the lightning channel exceeding 10 times the normal atmospheric pressure . This shock wave slows down quickly after a distance of a few meters (see above). When thunder is heard by the observer from a distance of 100 meters (328 ft), it consists of a single 'bang' like an explosion, however small sounds of "hissing" or "clicking" can be heard. When the observer is 1 km away (.6 mi), thunder will be heard as a rolling sound followed by a few loud claps.
Thunder can be heard up to a distance of 16 km (10 mi) if conditions are ideal. The thunder heard by a distant observer has a specific characteristic of a low frequency 'tickling' sound, like the sound produced by your stomach when you are hungry. The intensity of a sound, whether high or low, is caused by the strong absorption and spread of the high-frequency components of the initial sound waves, while the "chirping" sound is produced by the fact that sound waves are emitted from different locations along channel, which may be further or closer to the observer. The longer the channel, the longer the thunder can be heard. The human ear can pick up the sound of lightning if it is between 20-120 Hertz(Hz). Even so, a small part of the sound produced by lightning, 10%, cannot be heard by the human ear due to its frequency. Specially equipped devices can capture these types of sounds.
We can use thunder to find out how long the lightning channel was and how far it is from us. For example, if we see lightningnow and we start counting up to 9 seconds when we hear a loud sound like clapping, or like a loud boom then it means that lightning struck the earth at a distance of 3 km. Even so, when doing this counting, it is recommended that you count until you hear the first distinctive sound, loud and like a loud beat, and do not stop when you hear any sound because you can hear the end of the channel hidden in the cloud for the first time. they are not visible to the observer and may be just above you and not the actual lightning channel. Therefore, when you want to calculate this distance, listen carefully to the lightning and make the difference between the banging sounds,
