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 latter. Can you explain why?

Answer the following question giving explanations wherever necessary. Lightning 'and thunder take place in sky and at tlie same distance from us. Explain why-lightning is seen earlier and thunder is heard later.

Why the thunder is heard after the flash of lightning ?

Explain why, the flash of lightning reached us first and the sound of thunder is heard a little later.

When body slides down from rest along smooth inclined plane making angle of 45^(@) with the horizontal, it takes time T When the same body slides down from rest along a rough inclined plane making the same angle and through the same distance it is seen to take time pT , where p is some number greater that 1. Calculate late the coefficient of friction beween the body and the rough plane. .