According to the mathematical model, the wavelength has an inverse relationship with the frequency, the higher the frequency, the shorter the wavelength, and vice versa. The wavelength λ (lambda) is equal to the velocity v of the wave, divided by the frequency f:
[tex]f = \frac{c}{\lambda}[/tex]
For our case we have that
[tex]c = 8*10^7m/s[/tex]
[tex]\lambda = 4*10^{-7}m[/tex]
Replacing to find the frequency we have that
[tex]f = \frac{8*10^7}{4*10^{-7}}[/tex]
[tex]f = 2*10^{14} Hz[/tex]
Therefore the frequency in this material is [tex]f = 2*10^{14} Hz[/tex]
