$A$ 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 frequencies of sound waves is audible to human beings?

What is the ratio of the velocity of sound in hydrogen $\left(\gamma=\frac{7}{5}\right)$ to that in helium $\left(\gamma=\frac{5}{3}\right)$ at the same temperature? (Molecular weight of hydrogen and helium is $2$ and $4$ respectively)

The velocities of sound at the same pressure in two monatomic gases of densities ${\rho _1}$ and ${\rho _2}$ are $v_1$ and $v_2$ respectively. If ${\rho _1}/{\rho _2} = 2$,then the value of $\frac{{{v_1}}}{{{v_2}}}$ is:

$A$ sound wave of frequency $v \text{ Hz}$ initially travels a distance of $1 \text{ km}$ in air. Then, it gets reflected into a water reservoir of depth $600 \text{ m}$. The frequency of the wave at the bottom of the reservoir is $(V_{\text{air}} = 340 \text{ m/s}, V_{\text{water}} = 1484 \text{ m/s})$

$A$ source of frequency $f$ is emitting sound waves. If the temperature of the medium increases,then