If the density of oxygen is $16$ times that of hydrogen,what will be the ratio of their corresponding velocities of sound waves?

When a tuning fork vibrates,the waves produced in the fork are

The ratio of densities of nitrogen and oxygen is $14:16$. The temperature at which the speed of sound in nitrogen will be the same as that in oxygen at $55^oC$ is ..... $^oC$.

Use the formula $v=\sqrt{\frac{\gamma P}{\rho}}$ to explain why the speed of sound in air:
$(a)$ is independent of pressure,
$(b)$ increases with temperature,
$(c)$ increases with humidity.

$A$ firecracker exploding on the surface of a lake is heard as two sounds a time interval $t$ apart by a man on a boat close to the water surface. Sound travels with a speed $u$ in water and a speed $v$ in air. The distance from the exploding firecracker to the boat is

The Earth has a radius of $6400 \ km$. The inner core of $1000 \ km$ radius is solid. Outside it,there is a region from $1000 \ km$ to a radius of $3500 \ km$ which is in a molten state. Then again from $3500 \ km$ to $6400 \ km$,the Earth is solid. Only longitudinal $(P)$ waves can travel inside a liquid. Assume that the $P$ wave has a speed of $8 \ kms^{-1}$ in solid parts and of $5 \ kms^{-1}$ in liquid parts of the Earth. An earthquake occurs at some place close to the surface of the Earth. Calculate the time after which it will be recorded in a seismometer at a diametrically opposite point on the Earth if the wave travels along the diameter.