Lightning and thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain why?

AcademicPhysicsNCERTClass 8

To do:
We have to explain why thunder is heard a few seconds after the flash is seen while the flash and thunder are produced simultaneously.

Explanation:
Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen. Let us know about the speed of sound and light because the big difference between their speed is the main reason behind it:

Speed of light:
A light ray travels with the fastest speed which is nearly $3,00,000\ km/h$. The speed of light is the universal speed limit, it means that nothing can travel faster than a light ray.

Speed of the sound:
A sound wave travels with a speed of $343\ m/s$ in the air at $20^{\circ} C$ which is much less than the speed of light.

Flash is seen first, and thunder is heard later:
Since the speed of light is greater than the speed of sound, lightning travels faster than thunder. Hence, even though lightning and thunder take place at the same time, lightning is seen earlier than thunder can be heard.
raja
Updated on 10-Oct-2022 13:25:06

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