Write true or false for the following statement: Sound produced by a sounding body of frequency $300 \text{ Hz}$ covers $34 \text{ m}$ in the time the sounding body produces $30$ vibrations.

State whether the following statement is true or false:
The wavelength of $5\, MHz$ ultrasound in a medium where the velocity is $1540\, m s^{-1}$ is $0.3\, mm$.

Write true or false for the following statement: The distance between a crest and the next trough in a wave motion is $\lambda / 4$.

$A$ man stands $33\, m$ from a high wall and claps his hands. Will he hear an echo? (Given,velocity of sound is $330\, m s^{-1}$)

$(i)$ How do bats make use of ultrasonic waves to catch their prey? Explain.
$(ii)$ $A$ radar signal is reflected by an aeroplane and is received $2 \times 10^{-5} \text{ s}$ after it was sent. If the speed of these waves is $3 \times 10^{8} \text{ m s}^{-1}$,how far is the aeroplane?

What is $SONAR$?