The ratio of the speed of sound in nitrogen gas to that in helium gas,at $300 K$ is

$A$ steel rod $100\, cm$ long is clamped at its middle. The fundamental frequency of longitudinal vibrations of the rod is given to be $2.53\, kHz$. What is the speed of sound in steel? (in $km/s$)

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:

Explain which properties are necessary to understand the speed of mechanical waves.

What is the effect of humidity on sound waves when humidity increases?

The ratio of the speed of sound in helium gas to that in nitrogen gas at $295 \text{ K}$ is (Ratio of specific heats for helium is $5/3$ and that for nitrogen is $7/5$. Molecular weight for helium and nitrogen are $4$ and $28$ respectively.)