Question

A man, standing between two cliffs, claps his hands and starts hearing a series of echoes at intervals of one second. If the speed of sound in air is $340m{s}^{-1}$, the distance between the cliffs is :

• A. $680m$
• B. $1700m$
• C. $340m$
• D. $1620m$

Answer 1

The correct option is C $340m$

Let the distance of man from each cliff be $x$.

Thus time taken by sound to hit a cliff and return=$\frac{2x}{v}=1$

$⟹x=\frac{340}{2}m=170m$

Thus distance between the cliffs=$170m\times 2=340m$