Try the fastest way to create flashcards
Question

# Red light of wavelength 670 nm produces photoelectrons from a certain photoemissive material. Green light of wavelength 520 nm produces photoelectrons from the same material with 1.50 times the maximum kinetic energy. What is the material’s work function?

Solution

Verified
Step 1
1 of 4

To solve for the material work function $\phi$, first we show that maximum kinetic energy $K.E_{\textrm{max}}$, for the both red and green wavelengths $\left(\lambda_{r}=670\textrm{nm}\right)$, $\left(\lambda_{g}=520\textrm{nm}\right)$ can be calculated as:

$\begin{equation} K.E_{\textrm{max}}=E_{p}-{\phi}=\left[\frac{h\textrm{c}}{\lambda_{r}}\right]-{\phi} \end{equation}$

and

$\begin{equation} K.E_{\textrm{max}}=1.50E_{p}-{\phi}=1.50\left[\frac{h\textrm{c}}{\lambda_{g}}\right]-{\phi} \end{equation}$

Rearranging terms for the equation (2), we get:

\begin{align*} 0=-1.50\frac{h{\textrm{c}}}{\lambda_{r,g}}-{\phi} \end{align*}

## Recommended textbook solutions #### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

4th EditionISBN: 9780133942651 (8 more)Randall D. Knight
3,508 solutions #### Mathematical Methods in the Physical Sciences

3rd EditionISBN: 9780471198260 (1 more)Mary L. Boas
3,355 solutions #### Fundamentals of Physics

10th EditionISBN: 9781118230718 (3 more)David Halliday, Jearl Walker, Robert Resnick
8,971 solutions #### College Physics

11th EditionISBN: 9781305952300Chris Vuille, Raymond A. Serway
5,021 solutions