3 Tutor System
Starting just at 265/hour

# 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 .