Question

A sonar emits pulses on the surface of water which are detected after reflection from the bottom. If the time interval between the emission and detection of the pulse is 2s. Find the depth of water. Take the velocity of sound in water as 1531m/s

Answer 1

In 2s, the sound wave goes the bottom and went back again, hence it travels twice the distance.

Hence,

Time taken to reach the bottom = 2/2s = 1second

Speed of wave = 1531m/s

Distance = Speed*Time = 1531*1 = 1531 m

Answer 2

Speed = distance/time
=> distance = speed x time
Depth of water = (1531 x 2)/2 m = 1531 m