Which of the following principles is being used in $SONAR$ technology?

The velocity of sound in a gas at pressure $P$ and density $d$ is

$A$ granite rod of $60 \ cm$ length is clamped at its middle point and is set into longitudinal vibrations. The density of granite is $2.7 \times 10^3 \ kg/m^3$ and its Young's modulus is $9.27 \times 10^{10} \ Pa$. What will be the fundamental frequency of the longitudinal vibrations in $kHz$?

Derive the expression for the speed of a sound wave and obtain the equations for the speed of sound in different media.

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?

The speed of sound waves in a fluid depends upon: