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Homework Help: Determining Work Function

  1. Apr 28, 2009 #1
    1. The problem statement, all variables and given/known data

    When a monochromatic light with a wavelength of 254 nm falls onto the surface of a particular metal it causes a photocurrent to flow. A stopping voltage of 2.30 V is required to completely block the photocurrent. What is the work function of the material?

    2. Relevant equations
    KE = hf - Wo
    hf = hc/wavelength

    3. The attempt at a solution
    I keep getting a negative number which is an impossible answer for a work function.
    Any help would be greatly appreciated.

    Thank you.
  2. jcsd
  3. Apr 28, 2009 #2


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    Homework Helper

    Before solving convert stopping potential to energy units.(J)
    Show your calculations.
  4. Apr 29, 2009 #3
    Thanks for pointing that out. I had the wrong units which messed up everything.
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