(a) [tex]5.5\cdot 10^{14} Hz[/tex]
Explanation:
The relationship between wavelength, frequency and speed of an electromagnetic wave is:
[tex]v=f \lambda[/tex]
where v is the speed, f is the frequency, [tex]\lambda[/tex] is the wavelength.
For the light wave in the problem, we have:
[tex]v=3.00\cdot 10^8 m/s[/tex] is the speed of light
[tex]\lambda=5.50 \cdot 10^{-7} m[/tex] is the wavelength
Substituting these numbers into the equation, and re-arranging it, we find the frequency of the light wave:
[tex]f=\frac{v}{\lambda}=\frac{3\cdot 10^8 m/s}{5.5\cdot 10^{-7} m}=5.5\cdot 10^{14} Hz[/tex]
(b) [tex]1.8\cdot 10^{-15} s[/tex]
Explanation:
The period of a wave is equal to the reciprocal of the frequency:
[tex]T=\frac{1}{f}[/tex]
where f is the frequency of the wave, which we found in the previous part of the exercise. Substituting, we find:
[tex]T=\frac{1}{f}=\frac{1}{5.5\cdot 10^{14} Hz}=1.8\cdot 10^{-15} s[/tex]
