question_answer

A boy strikes the iron pipe with a stone. Another boy who keeps his ear close to the other end of the pipe heard two sounds in a short interval of time. Explain why?

Answer:

Since the velocity of sound waves in iron (solid) is greater than the velocity of sound waves in air, so the sound travelling through iron pipe is heard before the sound travelling through the air. Hence, the boy heard two sounds in a short interval of time.