Question

Question 1
A submarine emits a sonar pulse, which returns from an underwater cliff in 1.02 s. If the speed of sound in salt water is 1531 m/s, how far away is the cliff?

Answer 1

Time taken by the sonar pulse to return, t = 1.02 s
Speed of sound in salt water, $V=1531m{s}^{-1}$
Distance of the cliff from the submarine = Speed of sound $\times$ Time taken
Distance of the cliff from the submarine = $1.02\times 1531=1561.62m$
Distance travelled by the sonar pulse during its transmission and reception in water = 2 $\times$ Actual distance = 2d
Actual Distance, $d=\frac{Distanceoftheclifffromthesubmarine}{2}$ $=\frac{1561}{2}$ = 780.5 m