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Homework Help: Kinetic energy in volts

  1. Jan 22, 2008 #1
    1. The problem statement, all variables and given/known data

    Point A is at a potential of +240 V, and point B is at a potential of -120 V. An -particle is a helium nucleus that contains two protons and two neutrons;

    the neutrons are electrically neutral. An -particle starts from rest at A and accelerates toward B.

    When the -particle arrives at B, what kinetic energy (in electron volts) does it have?
    in eV

    2. Relevant equations

    3. The attempt at a solution

    W = q * (chng in V)

    q is the charge stored by a dialectric capacitor.

    and change in V is the electric potential difference.

    chng in V = Vb - Va = -360 V correct?

    so where does the q come from?
  2. jcsd
  3. Jan 22, 2008 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Let me give you the definition of an "electron volt:"

    The energy gained by an electron, in moving through a potential of one volt, is one electron volt.

    - Warren
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