Question

State one important property of waves used for echo depth sounding.

Answer 1

Ultrasonic waves are sound waves transmitted above the human-detectable frequency range, usually above $20,000Hz$.

Echo sounding is a type of SONAR used to determine the depth of water by transmitting sound pulses into water. The time interval between emission and return of a pulse is recorded, which is used to determine the depth of water along with the speed of sound in water at the time