(a) [tex]5.45 \cdot 10^{14} Hz[/tex]
The relationship between frequency and wavelength of an electromagnetic wave is given by
[tex]c=f \lambda[/tex]
where
[tex]c=3.00 \cdot 10^8 m/s[/tex] is the speed of light
[tex]f[/tex] is the frequency
[tex]\lambda[/tex] is the wavelength
In this problem, we are considering light with wavelength of
[tex]\lambda=5.50 \cdot 10^{-7} m[/tex]
Substituting into the equation and re-arranging it, we can find the corresponding frequency:
[tex]f=\frac{c}{\lambda}=\frac{3.00 \cdot 10^8 m/s}{5.50 \cdot 10^{-7} m}=5.45 \cdot 10^{14} Hz[/tex]
(b) [tex]1.83\cdot 10^{-15} s[/tex]
The period of a wave is equal to the reciprocal of the frequency:
[tex]T=\frac{1}{f}[/tex]
And using [tex]f=5.45 \cdot 10^{14} Hz[/tex] as we found in the previous part, we can find the period of this wave:
[tex]T=\frac{1}{5.45 \cdot 10^{14} Hz}=1.83\cdot 10^{-15} s[/tex]
