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Finding the Compton wavelength of the electron

  1. Mar 4, 2010 #1
    1. The problem statement, all variables and given/known data
    h/(mc) = ?
    where m is the mass of an electron

    2. Relevant equations

    3. The attempt at a solution
    h = 4.136*10^-15 eV*s
    m = 0.511 MeV/c^2
    c = 299792458 m/s

    So m*c (as long as I remember to multiply by 10^6) gives units of eV/c
    So h/(mc) gives units of s*c
    Using the values I've written here, I would get

    h/(mc) = 2.6998*10^-29 s*c

    But c has units of m/s, so I can get units of m by multiplying by the numerical value of c, right? Then I multiply by 10^9 to get units of nm, and I get

    h/(mc) = 8.09*10^-12 nm

    But this is wrong, because the answer is 0.002426 nm.

    I can't believe I can't do a simple plug-in problem, but, well, it should be easy enough to help me with.
  2. jcsd
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