An underwater sonar source operating at a frequency of $60 \, kHz$ directs its beam towards the surface. If the velocity of sound in air is $330 \, m/s$,the wavelength and frequency of waves in air are:

Write Newton's equation for the speed of a sound wave in air.

$A$ source $S$ of frequency $f_0$ and an observer $O$,moving with speeds $v_1$ and $v_2$ respectively,are moving away from each other. When they are separated by a distance $a$ at $t = 0$,a pulse is emitted by the source. This pulse is received by $O$ at time $t_1$. Then $t_1$ is equal to:

The enclosed air inside a closed box of rigid walls has pressure $P_1$. The density of air inside this box is constant. On heating the gas, the pressure of the enclosed air is increased from $P_1$ to $P_2$. Now it is observed that the sound travels $1.4$ times faster than at pressure $P_1$. The ratio $P_2/P_1$ is:

The temperature at which the speed of sound in air becomes double of its value at $0^oC$ is ...... $K$.

Frequency range of the audible sounds is