The speed of sound in oxygen $(O_2)$ at a certain temperature is $460 \, m/s$. The speed of sound in helium $(He)$ at the same temperature will be ............. $m/s$ (assume both gases to be ideal).

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 .... $^oC$

Mention the type of ultrasonic waves and their frequency.

An earthquake generates both transverse $S$ and longitudinal $P$ waves in the earth with speeds $4.5 \,km/s$ and $8.0 \,km/s$, respectively. $A$ seismograph records that the first $P$-wave arrives $3.5 \,min$ earlier than the first $S$-wave. From the seismograph, the epicentre of the earthquake is located at a distance of: (in $\,km$)

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ sound wave has higher speed in solids than gases.
Reason $R$: Gases have higher value of Bulk modulus than solids.
In the light of the above statements,choose the correct answer from the options given below:

$A$ 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.