What is an echo ?

(a) What is an echo? How is echo formed? (b) What is the minimum distance in air required from a sound reflecting surface to hear an echo (at 20^(@)C) ? (c) A man standing 825 metres away from a cliff (steep rock) fires a gun. After how long will he hear its echo? Speed of sound in air is 330m//s .

What is echo ? How is it formed ?

What is echo ? Why we cannot hear an echo in a small room ?

What is meant by aan echo ? Explain.

What is meant by an echo ? State two conditions necessary for an echo to be heard distinctly.

What is echo-location?