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Homework Help: Quantum Physics Problem

  1. May 1, 2005 #1
    In a photoelectric experiment, light is incident on a metal surfact. Photoelectrons are ejected, producing a current. A reverse potantial is applied and adjusted until the current drops to 0 (this is called the stopping potential). This fata is collected for stopping potentials (listed first) for four different frequencies (listed second): [typo volts that reads 0,] and 2E14Hz; 0.9V and 4E14Hz; 2V and 7E14Hz; 3V and 9.3E14Hz.

    Determine an experimental value for Planck's constant. What is the work function of the metal?

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    Can someone tell me what formulas to use?
     
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  3. May 1, 2005 #2

    Gokul43201

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  4. May 1, 2005 #3
    Well, I'm given two formulas for Photoelectric Effect wiht little about them. The only one that I have no idea what it is states: KE[max] = eV[0]. I know that eV is electron Volts, but I don't think that's what the formula is saying.
     
  5. May 2, 2005 #4

    Gokul43201

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    KE(max) : maximum kinetic energy (~0.5mv^2) of ejected photoelectron
    e : charge on the electron = 1.6 * 10^-19 coulombs
    V(0) : applied stopping potential in volts
     
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