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Homework Help: Speed of an Electron in an Electric Field

  1. Apr 18, 2008 #1
    1. The problem statement, all variables and given/known data

    . The problem statement, all variables and given/known data

    Two stationary positive point charges, charge 1 of magnitude 3.25 nC and charge 2 of magnitude 1.55nC , are separated by a distance of 57.0cm . An electron is released from rest at the point midway between the two charges, and it moves along the line connecting the two charges.

    find Vfinal of the electron when it is 10.0 cm from charge 1 the want the final answer in m/s

    i dont get any of this my professor went to fast. can anyone help?

    2. Relevant equations

    not sure

    3. The attempt at a solution
  2. jcsd
  3. Apr 18, 2008 #2


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    Staff: Mentor

    What is the equation for the electric field due to a point charge?

    What is the equation for the force on a charge due to an electric field?

    What is the equation relating force, mass and acceleration?

    What is the equation of motion of a mass experiencing a force?
  4. Apr 18, 2008 #3
    I figured out the Uinital=-2.42e-17J, Kinitial= 0J, Ufinal is -5.15e-17J where do i go from here
  5. Apr 18, 2008 #4


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    Homework Helper

    Hi HELLO11,

    Energy is conserved in this situation; but Uinitial is not equal to Ufinal. In what form is the rest of the energy at the final point? Once you have that you'll be able to find the speed of the electron.
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