To calculate this we will use the light equation:
[tex]c=[/tex]λ[tex]*f[/tex]
We have Frequency [tex]f=9.4* 10^{9}Hz [/tex].
We know that speed of light in vacuum is [tex]c =3.8* 10^{8} m/s [/tex].
Since a unit of speed of light is m/s, we can change the unit of frequency Hz to 1/s, since Hz means cycles per second (f=1/T).
So:
[tex]f=9.4* 10^{9}1/s [/tex]
[tex]c =3.8* 10^{8} m/s [/tex]
[tex]c=[/tex]λ[tex]*f[/tex]
⇒ λ[tex]= \frac{c}{f} [/tex]
⇒ λ[tex]= \frac{3.8* 10^{8}}{9.4* 10^{9}} [/tex]
⇒ λ[tex]=0.04 m[/tex]
