Find the frequency of the minimum distance between a compression and a rarefaction of a wire. If the length of the wire is $1\, m$ and the velocity of sound in air is $360\, m/s$,find the frequency in $sec^{-1}$.

$A$ plane sound wave passes from medium $1$ into medium $2$. The speed of sound in medium $1$ is $200 \, m/s$ and in medium $2$ is $100 \, m/s$. The ratio of the amplitude of the transmitted wave to that of the incident wave is:

Sound waves in air are

On a windless day,sound emanates isotropically from a point source. Rays of the sound waves emanated from a point source placed close to the ground are shown in the figure. Consider horizontal wind towards the left blowing with constant velocity,which is uniform everywhere. In the following figures,rays of sound waves in the presence of the wind are shown. Which one is the most correct representation?

$A$ man sets his watch by a whistle that is $2\, km$ away. How much will his watch be in error? (Speed of sound in air = $330\, m/s$)

Which of the following waves is used in sonography?