Answer:
f=4.37×10¹⁴ Hz
Step-by-step explanation:
Given data
λ =686nm=6.86×10⁻⁷m
c=3.00×10⁸ m/s
To find frequency
Solution
We can use the equation
λ f = c
where
λ is the wavelength of the wave, in meters
f is the frequency of the wave hertz ( Hz )
c is the speed of light
f=c/λ
f=3.00×10⁸/6.86×10⁻⁷
f=4.37×10¹⁴ Hz