Q67 of 199 Page 208

A sonar station picks up a return signal after 3 seconds. How far away is the object? (Speed of sound in water = 1440 m/s).

Time of echo = 3 s

speed of sound = 1440 m/s

Distance = (v × t)/2 = (1440 × 3)/2 = 2160 m

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

What is sonar? Explain its use.

Draw a neat and labelled diagram of the human ear. With the help of this diagram, explain the construction and working of the human ear.

In SONAR we use:

A. ultrasonic waves

B. infrasonic waves

C. radio waves

D. audible sound waves