Question

A boy claps his hands in front of a cliff and hears the reflected sound 2 seconds later. If the speed of sound is 340 m/s, the distance of the cliff from the boy is _______ and the minimum distance he should be away from the cliff should be not less than _____m in order to hear the echo​

Answer 1

Answer:

Let d be the distance of cliff from the boy . Therefore total distance covered by sound to go to cliff and  come back to boy after reflection from cliff ,  =2d ,

given v=340m/s,t=3s ,

we have , distance=speed×time ,

              2d=v×t=340×3 ,

or            d=340×3/2=510m

Explanation: