Answer:
The longest wavelength of light is 209 nm.
Explanation:
Given that,
Spring constant = 74 N/m
Mass of electron [tex]m= 9.11\times10^{-31}\ kg[/tex]
Speed of light [tex]c= 3\times10^{8}\ m/s[/tex]
We need to calculate the frequency
Using formula of frequency
[tex]f =\dfrac{1}{2\pi}\sqrt{\dfrac{k}{m}}[/tex]
Where, k= spring constant
m = mass of the particle
Put the value into the formula
[tex]f=\dfrac{1}{2\pi}\sqrt{\dfrac{74}{9.11\times10^{-31}}}[/tex]
[tex]f=1.434\times10^{15}\ Hz[/tex]
We need to calculate the longest wavelength that the electron can absorb
[tex]\lambda=\dfrac{c}{f}[/tex]
Where, c = speed of light
f = frequency
Put the value into the formula
[tex]\lambda =\dfrac{3\times10^{8}}{1.434\times10^{15}}[/tex]
[tex]\lambda=2.092\times10^{-7}\ m[/tex]
[tex]\lambda=209\ nm[/tex]
Hence, The longest wavelength of light is 209 nm.