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Electron question

  1. Aug 16, 2004 #1
    Simple question;

    For an electron, what is its velocity after it has been accelerated through 50V?

    I thought about equating 50eV to KE, but I know thats the wrong way, any ideas?

  2. jcsd
  3. Aug 16, 2004 #2


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    Why is that wrong ??

  4. Aug 16, 2004 #3
    dunno, it doesnt feel right? is that way the correct way?
  5. Aug 16, 2004 #4


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    It's correct because an electron volt is defined as the energy gained by an electron (elementary charge) when accelerated through a potential difference of 1 V. So 50V imparts 50eV to the electron, which is equal to its final kinetic energy. From that you can easily calculate it's final velocity.
  6. Aug 16, 2004 #5
    Don't forget to consider initial energy, velocity, direction etc.
  7. Aug 17, 2004 #6
    abd dont forget to calculate that using relativistic Kinetic Energy.
  8. Aug 17, 2004 #7
    I don't think that's needed here; the electron's rest mass is about 0.5MeV and we're talking a KE of 50eV.
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