# Homework Help: Einstein's equation

1. Nov 14, 2012

### chikis

1. The problem statement, all variables and given/known data
Calculte the frequency of the proton with a kinetic energy of 1.97*10-16ev if the work function of the metal is 1.33*10-16
(IeV=1.6*10-19J, h=6.60*10-34Js

2. Relevant equations

E = hf-hfo=hf-Wo

Where E= maximum kinetic energy

h= Plancks's constant
Wo=hfo=work function

f=frequency of the incidented light

3. The attempt at a solution

from E = hf-Wo, we have

f = E+Wo/h
f = 1.97*10-16+1.33*10-16/6.60*10-34

Where can I subtitute that one into?

Last edited: Nov 14, 2012
2. Nov 14, 2012

### voko

The problem's statement does not make sense. Einstein's equation, which is presumably the one dealing with photoelectric emission, is about electrons and photons, not protons.

What is really given and what is required to determine?

3. Nov 14, 2012

### chikis

The problem says:

Calculte the frequency of the proton with a kinetic energy of 1.97*10-16ev if the work function of the metal is 1.33*10-16
(IeV=1.6*10-19J, h=6.60*10-34Js

4. Nov 14, 2012

### haruspex

Fairly clearly 'proton' is a typo for 'photon'
Another typo: should be '1ev'
I hope you mean f = (E+Wo)/h

5. Nov 14, 2012

Yes!