Question

An echo-sounder in a fishing boat receives an echo from a shoal of fish 0.45s after it was sent. If the speed of sound in water is 1500 m/s, how deep is the shoal?

Answer 1

Given : t = 0.45 s, v = 1500 m/s, 

To Find : depth (d)

Formula : speed (v) = distance/time

Calculation : 

For an echo distance travelled by the sound wave = 2 × (distance between echo sounder and shoal) (d)