Question

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 = 1531 m s⁻¹

Total distance covered by the sonar pulse = Speed of sound × Time taken

Total distance covered by the sonar pulse .....(i)

Let d be the distance of the cliff from the submarine.

Total distance covered by the sonar pulse = 2d
$$\begin{gathered} \Rightarrow 2d=1561.62[\mathrm{From}(\mathrm{i}\left)\right] \\ \Rightarrow d=780.81\mathrm{m} \end{gathered}$$