If the frequency of a sound wave is $n$ and its velocity is $v$,what will be the new velocity if the frequency is changed to $4n$?

Which of the following is a longitudinal wave?

The velocity of sound in air at $20^{\circ} C$ and $1 \text{ atm}$ pressure is $344.2 \text{ m/s}$. At $40^{\circ} C$ and $2 \text{ atm}$ pressure, the velocity of sound in air is approximately: (in $\text{ m/s}$)

The speed of a longitudinal wave in a metallic bar is $400 \ m/s$. If the density and Young's modulus of the bar material are increased by $0.5\%$ and $1\%$ respectively, then the speed of the wave is changed approximately to . . . . . . $m/s$.

In a medium,sound travels $2 \, km$ in $3 \, sec$ and in air,it travels $3 \, km$ in $10 \, sec$. The ratio of the wavelengths of sound in the two media is

The depth of the sea is measured by means of an echo. If the time between the moment the sound is produced and received is $3.52 \,s$, then the depth of the sea is (The compressibility of sea water is $4.84 \times 10^{-10} \,m^2 \,N^{-1}$ and its density is $1024 \,kg \,m^{-3}$): (in $km$)