Sound travels in rocks in the form of

At what temperature is the velocity of sound double that of its velocity at $0^{\circ}C$?

What is the velocity of a wave in a monoatomic gas having a pressure of $1 \, kPa$ and a density of $2.6 \, kg/m^3$?

$A$ person standing on an open ground hears the sound of a jet aeroplane coming from the north at an angle of $60^{\circ}$ with the ground level. However,he finds the aeroplane right vertically above his position. If $\upsilon$ is the speed of sound,what is the speed of the plane?

The minimum distance of the reflector surface from the source to hear the echo of sound is ..... $m$.

$A$ plane sound wave passes from medium $1$ into medium $2$. The speed of sound in medium $1$ is $200 \, m/s$ and in medium $2$ is $100 \, m/s$. The ratio of the amplitude of the transmitted wave to that of the incident wave is: