Question

An observer stands at a certain distance away from a cliff and produces a loud sound. He hears the echo of the sound after $1.8s.$ Calculate the distance between the cliff and the observer if the velocity of sound in air is $340m{s}^{-1}$.

Answer 1

Step 1. Given:

$Time\left(t\right)=1.8s$

Velocity of sound (v) $=340\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$

Step 2. Finding the distance between observer and cliff

$Totaldis\tan cetravelbythesound\left(d\right)=Velocityofsound\times Time$

$=340\times 1.8$

$Totaldis\tan ce=612m$

Sound travel from observer to cliff and cliff to observer the total distance is d.

$\therefore$ Distance between observer and cliff $=\frac{Totaldis\tan cetravelledbythesound}{2}$

$=\frac{d}{2}$

$=\frac{612}{2}$

$=306m$

Hence, the distance between observer and cliff is $306m$.