Question

The speed of light is more than the speed of sound. Due to this, we always hear the thunder a little after we see the flash of lightning.

Explanation:

Measurements, of the speed of light and sound, tell us that light propagates very fast as compared to sound. The speed of sound in air is nearly 330 ms-¹ (or 0.33 km per second) and the speed of light (in vacuum) is as high as (nearly) 3 lakh kilometres per second. Light, thus, propagates nearly a million times faster than the sound. Hence, when lighting and thunder occur together, the flash of lighting reaches us in practically zero time. The sound of the thunder, however, takes a few seconds to reach us. We, therefore, hear the thunder a little later after seeing the flash of light.