Newton assumed that sound propagation in a gas takes place under which condition?

Oxygen is $16$ times heavier than hydrogen. Equal volumes of hydrogen and oxygen are mixed. The ratio of the speed of sound in the mixture to that in hydrogen is

$A$ car is moving with a speed of $72 \,km/h$ towards a hill. The car blows its horn at a distance of $1800 \,m$ from the hill. If the echo is heard after $10 \,s$, the speed of sound (in $m/s$) is:

The pressure wave,$P = 0.01 \sin(1000t - 3x) \, N m^{-2}$,corresponds to the sound produced by a vibrating blade on a day when atmospheric temperature is $0 \, ^oC$. On some other day when temperature is $T$,the speed of sound produced by the same blade and at the same frequency is found to be $336 \, m s^{-1}$. The approximate value of $T$ is .... $^oC$

Why are the speeds of longitudinal and transverse waves in a solid different? Explain.

$A$ man standing on a cliff claps his hands and hears the echo after $1 \, s$. If the sound is reflected from another mountain and the velocity of sound in air is $340 \, m/s$,then the distance between the man and the reflection point is ..... $m$.