1. Not finding help here? Sign up for a free 30min 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!

Wavelength of ejected electrons

  1. Nov 15, 2013 #1
    1. The problem statement, all variables and given/known data

    The threshold frequency of a metal is 3.184 x 10^14 Hz. If a photon of wavelength 368 nm strikes the surface of the metal, what is the wavelength of the ejected electron?

    2. Relevant equations
    f (frequency) = c/(wavelength)
    Eincident = Ethreshold + KE
    E=fv(wavelength)

    3. The attempt at a solution
    Oh man... here it is. I bet I'm missing something huge but it's just been killing me.

    photo 1 copy.jpg

    photo 2 copy.jpg
     
  2. jcsd
  3. Aug 14, 2017 #2

    TeethWhitener

    User Avatar
    Science Advisor
    Gold Member

    You're good up through the energy calculation. From there you can use:
    $$KE = \frac{p^2}{2m}$$
    to get a value for your momentum. Then just plug that number in to:
    $$\lambda = \frac{h}{p}$$
    and you get your answer.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted