Name an animal which navigates and find food by echolocation.

The audible range of frequencies of an average human ear is from 20 Hz to 20 kHz. Calculate the corresponding wavelengths. (Speed of sound in air is 344 m s^-1).

Define the following terms:

(1) Echolocation

(2) Echocardiography, and

(3) Ultrasonography.

Which of the two produces ultrasonic waves: porpoise or whale?

What is sonar? Explain its use.