D) The particle displacement due to a sound wave is given by: y = 4.25x10-3 sin[200πt – (2πx /800)]Where x is measured in cm and t in seconds. Write down the amplitude, velocity , wavelength, frequency, andTime period of the wave.Notes:IeI= 1.6 x10-19 C, me=9.1x10-31 kg, mp = 1.67x10-27 Kg, h= 6.62x10-34 J.s, c= 3x108 m/s

Respuesta :

Given,

[tex]y=4.25\times10^{-3}\sin \lbrack200\pi t-(\frac{2\pi x}{800})\rbrack[/tex]

The wave equation of a particle is,

[tex]y=A\sin (\omega t-kx)[/tex]

Where

• A is the amplitude.

,

• ω is the angular velocity.

,

• k is the wavenumber.

On comparing the two equations,

Amplitude, A=4.25×10⁻³

Angular velocity, ω=200π rad/s200

The wavenumber, k=2π/800 /m

The velocity of the particle is equal to the time derivative of its displacement.

Thus, the velocity is,

[tex]\begin{gathered} v=\frac{dy}{dt} \\ =\frac{d}{dt}(A\sin (\omega t-kx))_{} \\ =A\omega\cos (\omega t-kx) \end{gathered}[/tex]

On substituting the known values, the velocity is,

[tex]\begin{gathered} v=4.25\times10^{-3}\times200\pi\times\cos \lbrack200\pi t-(\frac{2\pi x}{800})\rbrack \\ =0.85\pi\cos \lbrack200\pi t-(\frac{2\pi x}{800})\rbrack \end{gathered}[/tex]

The wavelength is given by,

[tex]\lambda=\frac{2\pi}{k}[/tex]

On substituting the known values,

[tex]\begin{gathered} \lambda=\frac{2\pi}{(\frac{2\pi}{800})} \\ =800\text{ m} \end{gathered}[/tex]

Thus the wavelength is 800 m

The frequency is given by,

[tex]f=\frac{2\pi}{\omega}[/tex]

On substituting the known values,

[tex]\begin{gathered} f=\frac{2\pi}{200\pi} \\ =0.01\text{ Hz} \end{gathered}[/tex]

Thus the frequency is 0.01 Hz

The period is given by,

[tex]T=\frac{1}{f}[/tex]

On substituting the known values,

[tex]\begin{gathered} T=\frac{1}{0.01} \\ =100\text{ s} \end{gathered}[/tex]

Thus the time period of the wave is 100 s