If the frequency of a tuning fork is $400 \, Hz$ and the speed of sound in air is $340 \, m s^{-1}$,find how far sound travels when the tuning fork makes $16$ vibrations. (in $, m$)

State the relationship between frequency and time period of a wave. The wavelength of vibrations produced on the surface of water is $2 \, cm$. If the wave velocity is $16 \, m s^{-1}$, find its frequency and time period.

$(i)$ Which property of sound wave determines:
$(a)$ loudness
$(b)$ pitch?
$(ii)$ $A$ $SONAR$ station picks up a return signal after $3 \ s$. How far away is the object? (Speed of sound in water is $1440 \ m \ s^{-1}$)
$(iii)$ How can reverberations in a big hall or auditorium be reduced?

Why do we hear the sound produced by the humming bees while the sound of vibrations of a pendulum is not heard?

$A$ laboratory uses an ultrasonic scanner to trace a tumour in tissue. The operating frequency of the scanner is $4.2 \times 10^{6} \text{ Hz}$. Calculate the wavelength of sound in the tissue if the speed of the sound is $1700 \text{ m s}^{-1}$.

Explain how the human ear works in the transmission of sound waves to the brain.