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Rest energy of the electron - calculation discrepancy

  1. Aug 9, 2015 #1
    When I use E=mc2 to calc. the rest energy of an electron, I get .512Mev not .511Mev. I am using 9.109x10-31 kg for the rest mass of an electron and 2.9979x10^8 m/s for the speed of light in a vacuum.
    Can anyone tell me why there ís a discrepancy between my results and the accepted answer?
  2. jcsd
  3. Aug 9, 2015 #2


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    Staff: Mentor

    What are you using as the conversion factor between Joules and Mev?
  4. Aug 9, 2015 #3
    You found my mistake. I was using 1.6x10-19joules equals 1 eV, instead of 1.602x10-19.
    Thank you for your help.
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