A wave is represented by the equation
`y=0.1 sin (100pit-kx)`
If wave velocity is `100 m s^(-1)`, its wave number is equal to

Options

A. 1 m
B. 2 m
C. `pi` m
D. `2pi` m

Answer

C

Explanation

`y=0.1sin(100pit-kx)`
Comparing it with `y=asin(omegat-kx)`, we get
`omega=100pi`
As wave velocity, `v=(omega)/(k)therefore k=(omega)/(v)=(100pi)/(100)=pi`
Wavelength, `lambda=(2pi)/(k)=(2pi)/(pi)=2m`