If the velocity of sound in a gas is $360\, m/s$ and the distance between a compression and the nearest rarefaction is $1\, m$,then the frequency of sound is ..... $Hz$.

$A$ man stands in front of a hillock and fires a gun. He hears an echo after $1.5\, s$. The distance of the hillock from the man is ...... $m$ (velocity of sound in air is $330\, m/s$).

$A$ 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:

Calculate the temperature at which the speed of sound will be two times its value at $0\,^oC$. (in $,K$)

The mass of one mole of a gas is $22.4 \times 10^{-3} \ kg$ and its specific heat ratio is $1.6$. The speed of sound in the gas at $STP$ is nearly: (in $m/s$)

The speed of sound in oxygen $(O_2)$ at a certain temperature is $460 \,ms^{-1}$. The speed of sound in helium $(He)$ at the same temperature will be (assume both gases to be ideal): (in $\,ms^{-1}$)