How do u get the wave number

The wavelength is the spatial period of the wave, the distance over which the wave's shape repeats. It is usually given in meters (m).

The wave number $k$ is defined as:

where:

• $k$ is the wave number (in radians per meter, $\text{rad/m}$ or $\text{m}^{-1}$)
• $\pi$ is the mathematical constant pi (approximately 3.14159)
• $\lambda$ is the wavelength (in meters, m)

Example:
If a wave has a wavelength of $\lambda = 0.5 \, \text{m}$, then its wave number would be: