Question

A man stands in between two cliffs and fires a gun. He hears two successive echoes after 3 seconds and 5 seconds. What is the distance between two cliffs? [Speed of sound $=330m{s}^{-1}]$

• A. 1320 m
• B. 1400 m
• C. 1500 m
• D. 1520 m

Answer 1

The correct option is A 1320 m

Distance of person from nearer cliff, $\left(d_1\right)$
$=\frac{v\times t}{2}\Rightarrow d_1=\frac{330\times 3}{2}=495m$
Distance of person from farther cliff, $d_2=\frac{v\times t}{2}$
$d_2=\frac{330\times 5}{2}=825m$
Total distance between two cliffs
$=d_1+d_2$
$=(495+825)$
$=1320m$.