Question

Light with a wavelength of 5.0 . 10-7 m strikes a surface that requires 2.0 ev to eject an electron. Calculate the frequency of the glven wave.

1.5 x 102
6.0 x 1014
17 x 10-15
6.0 x 10-16​

Answer 1

`6.0\cdot 10^(14) Hz`

Step-by-step explanation:

The frequency and the wavelength of an electromagnetic wave are related by the wave equation:

`c=f \lambda`

where

`c=3.0\cdot 10^8 m/s` is the speed of light

f is the frequency

`\lambda` is the wavelength

For the light wave in this problem,

`\lambda = 5.0\cdot 10^(-7) m` is the wavelength

So, solving the equation for f, we find its frequency:

`f=(c)/(\lambda)=(3.0\cdot 10^8)/(5.0\cdot 10^(-7))=6.0\cdot 10^(14) Hz`