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?

Time (t) taken by the sonar pulse to return = 1.02 s

Speed (v) of sound in salt water = 1531 m/s

Distance travelled by sonar pulse
= Speed of sound × Time taken \( =1531 \ × \ 1.02 \ \)
\( = \ 1561.62 \ m \)

Distance of the cliff from the submarine
\( = \ \frac{Total \ distance \ travelled \ by \ sonar \ pulse}{2} \)

\( =\frac{1561.62}{2} \)

\(\Rightarrow \) Distance of the cliff from the submarine = 780.81 m .