Question

The velocity of sound in air at ${20}^{o}C$ and $1$ atm pressure is $344.2m/s$. At ${40}^{o}C$ and $2$ atm pressure the velocity of sound in air is approximately

• A. $350m/s$
• B. $356m/s$
• C. $363m/s$
• D. $370m/s$

Answer 1

Answer: (B)

$356m/s$

Speed of sound in air is proportional to $\sqrt{T}$

Hence $\frac{v_2}{v_1}=\sqrt{\frac{T_2}{T_1}}$

$⟹\frac{v_2}{344.2}=\sqrt{\frac{273+40}{273+20}}$

$=356m/s$