Question

Give reasons as to why during a thunderstorm, the sound of thunder is heard much later than the flash of lightning is seen.

Answer 1

Hint: As we all know that 2 basic requirements are necessary for the formation of thunderstorms i.e. instability in rising air, and moisture. The density of air should be less for the formation of thunderstorms. The heating of air is done by the surface of air and to reduce the density.


Complete step by step solution: When the light of thunderbolt is travelling from the clouds to the ground then the hot air surrounding the bolt has no time to expand. The hot air pressure becomes very low. When the air cools the previous hot air compressed from ten to hundred times the actual atmospheric pressure. So, the air suddenly explodes and a high intensity shock wave is released which we hear as a high pitch sound.

Since the speed of the light is far higher than the speed of the sound, hence the sound of the thunder is heard much later after the light bolt.

Additional Information: As we have seen many times that when a thunderbolt falls on a house or pole, it takes only one by 2000 of a second for the thunder light to travel through the air to the target. The explosion sound that we hear from the thunderbolt lightning generally comes from the sudden expansion of air which is surrounding the bolt of thunder light.


Note: When a thunder of light travels from cloud to the surface of earth then it returns to the cloud again after striking the surface which is then following the same trajectory. Hence, during this process the temperature of the surrounding air increases to 26500 degrees centigrade.