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Homework Help: Electrostatics Question

  1. Nov 28, 2006 #1
    1. The problem statement, all variables and 'given'/'known' data
    A proton accelerates from rest from plate X to plate Y. If the potential difference between the 2 plates is 60.0V, what is the speed of the proton when it reaches plate Y?

    2. Governing equations
    V = E/q
    Ekf - 1/2mv^2

    3. The attempt at a solution
    E = (60V)(1.6x10^-19C)
    E = 9.6x10^-18 V/m

    Ekf = 1/2mv^2
    9.6E-18 J = 1/2(9.11x10^-31kg)v^2

    EDIT: added units

    And when I solve for v my answer is not correct. So I'm making a mistake somewhere.

    Last edited: Nov 28, 2006
  2. jcsd
  3. Nov 28, 2006 #2


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    Staff: Mentor

    Good job posting the question. I'm having trouble checking your work because units are not shown throughout. Could you please include units on things like the 1.6x10^-19 term, etc.? Thanks.
  4. Nov 28, 2006 #3
    added units
  5. Nov 28, 2006 #4
    The mass of a proton is not 9.11e-31 Kg!
  6. Nov 28, 2006 #5
    Oh dear, how could I mix that up.

    I did it as an electron...

    Problem solved, thanks
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