Question

A man is stationed between 2 parallel cliffs fires a gun.He hears the first echo after 1.5 seconds and the next after 2.5 seconds . What is the distance between the cliffs and when does he hear the third echo? take the speed of sound go to be 340m/s
PLS ANSWER

Answer 1

Suppose the two cliffs are A and B which are at the distances x and y from the man respectively.

Consider that the echo of 1.5 sec and 2.5 sec are produced by are produced by cliff A and B.

2x = 340 x 1.5

x = 255 m

2y = 340 x 2.5

y = 425 m

Distance between the cliff = x + y = 680 m

The third echo will be heard after 1.5 sec from the time when the second echo is heard.

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