Question

What are the effects of the velocity of sound on changing pressure and temperature?

Answer 1

The velocity of sound:

The velocity of sound in air ($V$) can be given by the formula as shown-

$V=\sqrt{\raisebox{1ex}{$\gamma P$}\!\left/ \!\raisebox{-1ex}{$\rho $}\right.}$

Here $\gamma$ represents the ratio of specific heats, which is equal to 1.4 for air.

$P$ represent the pressure of the air.

$\rho$ represent the density of the air.

1. As the pressure ($P$) of the air increase the density of air also increase so the value of $\frac{P}{\rho }$ the ratio remains the same, so on changing pressure, velocity of sound does not change.
2. As the temperature of air increases, it expands so the density of air $\rho$ decrease, which increases the velocity of the sound and vice versa.

Hence, on changing pressure, the velocity of sound does not change and on changing temperature it increases or decrease as temperature increase or decrease respectively.