$A$ mechanical wave (sound wave) in a gas is:

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 $\text{ m/s}$)

Mention the type of ultrasonic waves and their frequency.

What is the ratio of the speed of sound in nitrogen gas to that in helium gas at the same temperature of $300 \, K$?

$A$ steel rod of length $100 \, cm$ is clamped at the middle. The frequency of the fundamental mode for the longitudinal vibrations of the rod is ..... $kHz$ (Speed of sound in steel $= 5 \, km \, s^{-1}$)

It takes $2.0 \ s$ for a sound wave to travel between two fixed points when the day temperature is $10^{\circ}C$. If the temperature rises to $30^{\circ}C$,the sound wave travels between the same fixed points in ...... $s$.