The frequency of a sound wave is $n$ and its velocity is $v$. If the frequency is increased to $4n$,the velocity of the wave will be

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 $\,km$)

$A$ 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.

Mention the type of ultrasonic waves and their frequency.

Write the equation for the speed of a sound wave in metals.

An underwater sonar source operating at a frequency of $60 \, kHz$ directs its beam towards the surface. If the velocity of sound in air is $330 \, m/s$,the wavelength and frequency of waves in air are: