In general, the velocity of sound in air varies directly as the square root of temperature measured in kelvin.

That V \( \propto \sqrt{T} \implies V^2 \propto T. \\

\text{Therefore} \frac{V^2_1}{T_1} = \frac{V^2_2}{T_2} \\

\text{Thus Let } V_1 = 4m/s \\
T_1 = 10K \\
\text{Therefore } V_2 = 2V_1 = 8m/s \\

\implies \frac{4^2}{10} = \frac{8^2}{T_2} \\

T_2 = \frac{64 \times 10}{16} = 40K\\

T_2 = 4T_1 \)

Thus when the velocity of sound in air is doubled, it's absolute temperature will be quadrupled.