Sound waves travel fastest in

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

$A$ plane wave of sound traveling in air is incident upon a plane surface of a liquid. The angle of incidence is $60^{\circ}.$ The speed of sound in air is $300 \, m/s$ and in the liquid it is $600 \, m/s.$ Assume Snell's law to be valid for sound waves.

The temperature at which the speed of sound in air becomes double of its value at $0^oC$ is ...... $K$.

$A$ big explosion on the moon cannot be heard on the earth because

Which of the following statements are wrong about the velocity of sound in air?