Sound Waves in Gases

The atomic mass of iodine is $127 \mathrm{g} {\mathrm{mol}}^{-1}$. A standing wave in iodine vapour at $400 \mathrm{K}$ has nodes that are $6.77 \mathrm{cm}$ apart when the frequency is $1000 \mathrm{Hz}$. At this temperature, is iodine vapour monoatomic or diatomic?

A gas is a mixture of two parts by volume of hydrogen and one part by volume of nitrogen at STP. If the velocity of sound in hydrogen at $0°\mathrm{C}$ is $1300 \mathrm{m} {\mathrm{s}}^{-1}$. Find the velocity of sound in the gaseous mixture at $27°\mathrm{C}$.

Helium is a monoatomic gas that has a density of $0.179 \mathrm{Kg} {\mathrm{m}}^{-3}$ at a pressure of $76 \mathrm{cm}$ of mercury and a temperature of $0 °\mathrm{C}$. Find the speed of compressional waves (sound) in Helium at this temperature and pressure.

A sound wave in air has a frequency of $300 \mathrm{Hz}$ and a displacement amplitude of $6.0\times {10}^{-3} \mathrm{mm}$. For this sound wave calculate the
$\left(\mathrm{a}\right)$ pressure amplitude
$\left(\mathrm{b}\right)$ intensity
$\left(\mathrm{c}\right)$ sound intensity level (in $\mathrm{dB}$).

Speed of sound $=344 \mathrm{m} {\mathrm{s}}^{-1}$ and density of air $=1.2 \mathrm{kg} {\mathrm{m}}^{-3}$.

Calculate the speed of sound in oxygen at $273 \mathrm{K}$.

Calculate the difference in the speeds of sound in air at $-3°\mathrm{C}, 60 \mathrm{cm}$ pressure of mercury, and $30°\mathrm{C}, 75 \mathrm{cm}$ pressure of mercury. The speed of sound in air at $0°\mathrm{C}$ is $332 \mathrm{m} {\mathrm{s}}^{-1}$.

Calculate the temperature at which the velocity of sound in air is double its velocity at $0°\mathrm{C}$.

The pressure variation in a sound wave in air is given by,
$\Delta p=12\sin (8.18x-2700t+\pi /4) \mathrm{N} {\mathrm{m}}^{-2}$
Find the displacement amplitude. Density of air $=1.29 \mathrm{kg} {\mathrm{m}}^{-3}$.

A typical loud sound wave with a frequency of $1 \mathrm{kHz}$ has a pressure amplitude of about $10 \mathrm{Pa}$
$\left(\mathrm{a}\right)$ At $t=0,$ the pressure is a maximum at some point ${\mathrm{x}}_1$. What is the displacement at that point at $t=0 ?$
$\left(\mathrm{b}\right)$ What is the maximum value of the displacement at any time and place? Take the density of air to be $1.29 \mathrm{kg}/{\mathrm{m}}^3$ and speed of sound in air is $340 \mathrm{m}/\mathrm{s}$

A plane sound wave passes from medium $1$ to medium $2$. The speed of sound in medium $1$ is $200 \mathrm{m} {\mathrm{s}}^{-1}$and in medium $2$ is $100 \mathrm{m} {\mathrm{s}}^{-1}$. The ratio of amplitude of the transmitted wave to that of incident wave is

A plane wave of sound travelling in air is incident upon a plane water surface. The angle of incidence is $60°$. If the velocity of sound in air and water are $330 \mathrm{m} {\mathrm{s}}^{-1}$ and $1400 \mathrm{m} {\mathrm{s}}^{-1}$ respectively, then the wave undergoes,

Using the fact that hydrogen gas consists of diatomic molecules with $M=2\times {10}^{-3} \mathrm{kg} {\mathrm{mol}}^{-1}$, find the speed of sound in hydrogen at $27°\mathrm{C}.$

Determine the speed of sound waves in water, and find the wavelength of a wave having a frequency of $242 \mathrm{Hz}$. Take $B_{\text{water }}=2\times {10}^9 \mathrm{Pa}$.

Oxygen is $16$ times heavier than Hydrogen. At $NTP$, equal volumes of Hydrogen and Oxygen are mixed. The ratio of speed of sound in the mixture to that in Hydrogen is,

A tuning fork of frequency $500 \mathrm{Hz}$ is sounded on a resonance tube. The first and second resonances are obtained at $17 \mathrm{cm}$ and $52 \mathrm{cm}$. The velocity of sound is,

When a sound wave travels from water to air, it

The temperature at which the velocity of sound in oxygen will be the same as that of nitrogen at $15 °\mathrm{C}$ is

Longitudinal waves are possible in

Velocity of sound in vacuum is