Answer:
Echo
Step-by-step explanation:
The process is called echo. Echo is the sound heard after the reflection of sound wave from a plane surface
Time = total distance traveled (2d) divided be velocity of sound.
One of the application of echo is to determine the depth of as sea bed from a ship
The principles involves sending a sound impulse down into the sea bed and detecting with a receiver the impulse reflected back after striking the sea bed.
Depth of sea bed is given as
D= V×t/2.