(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

a student carried out a photoelectric experiment by shining visible light on a clean piece of cesium metal. She determined the kinetic energy of ejected electrons by applying a retarding voltage such that the current due to the electrons read exactly 0. The condition was reached when eV=(1/2)(m sub e)(velocity)^2 where e is electric charge and V is the retarding potential. Her results are as follows:

wavelength / nm---405-------435.8----480------520-----577.7----650

V / volt-----------1.475------1.268----1.027----0.886---0.667----0.381

rearrange equation to read: frequency= (phi)/(h) + (e/h)V

determine the values of h (planks constant) and phi (work function) graphically.

2. Relevant equations

The equation the book rearranged was hv=(phi)+ (1/2)(m sub e)(velocity)^2

In class the following day our teacher gave us the equation that I believe he some how derived from the rearranged equation: 1/wavelength=(c/h)(eV)+ c(phi)/h^2 or h2 my notes were hurried and I cant really tell... not to mention I just dont see how either one could be derived unless i'm missing something (probable)

3. The attempt at a solution

I've tried playing with it some but I really dont know where to start with this question.

I'm not even positive what it is asking for. I assume its asking me to find plank's constant and the work function from the data given but am I supposed to make a scatter plot of my results or what?

I think I'm just having trouble wrapping my brain around exactly what it wants and trying to find a method of attack.

Any help on this would be extremely useful

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Physical Chemistry photoelectric question stumped

**Physics Forums | Science Articles, Homework Help, Discussion**