Question

A sonar echo takes 8.8s to return from a shark. How far away is the shark?

Speed of the sound in sea water at ${25}^{\circ }C$ is $1533m{s}^{-1}$

• A. $348m$
• B. $5720m$
• C. $6745m$
• D. $13490m$

Answer 1

The correct option is D $13490m$

Total time is taken by the signal

$T=8.8s$
Time taken by the signal to reach the shark

$t=\frac{T}{2}$

$\Rightarrow t=\frac{8.8}{2}$

$\Rightarrow t=4.4s$
Speed of sound in sea water at ${25}^{\circ }C=1533m{s}^{-1}$
Distance of shark,

$d=vt$

$\Rightarrow d=1533\times 4.4$

$\Rightarrow d=13490m$