1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Einstein's equation

  1. Nov 14, 2012 #1
    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

    What about the IeV=1.6*10-19J?

    Where can I subtitute that one into?
     
    Last edited: Nov 14, 2012
  2. jcsd
  3. Nov 14, 2012 #2
    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?
     
  4. Nov 14, 2012 #3
    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
     
  5. Nov 14, 2012 #4

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Fairly clearly 'proton' is a typo for 'photon'
    Another typo: should be '1ev'
    I hope you mean f = (E+Wo)/h
     
  6. Nov 14, 2012 #5
    Yes!
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook