Question

Question 20
A sonar device on a submarine sends out a signal and receives an echo 5 s later. Calculate the speed of sound in water if the distance of the object from the submarine is 3625 m.

Answer 1

Given, time taken to hear the echo, t = 5 s and distance of the object from the submarine, d = 3625 m
Therefore total distance travelled by the sonar waves during the transmission and reception in water = 2d
Let $v$ be the velocity of sound in water.
Velocity of sound in water, $v=\frac{distance}{time}=\frac{2d}{t}=2\times \frac{3625}{5}=1450m{s}^{-1}.$