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Homework Help: Eletric force problem

  1. Apr 6, 2010 #1
    1. The problem statement, all variables and given/known data

    the magnitude of the electric field strength between two oppositly charged parallel metal plate is 2.0 x 10 3 newtons per coulomb. point p is located midway between the plates.

    an electron is located at point p between the plates. caculate the magnitude of the force exerted by the electric field

    2. Relevant equations

    Felect = k • Q1 • Q2 / d2

    k = 9.0 x 109 N•m2
    q1 = 2.0 x 10 3
    q2 = 2.0 x 10 3
    d = missing

    3. The attempt at a solution

    how do i figure out the distance for this problem?
  2. jcsd
  3. Apr 6, 2010 #2
    If you've already got the electric field, you don't need a distance; you can just use the fact that F=qE. If your field exerts 2000 Newtons of force on every Coulomb of charge in it, and your particle's charge is -1.6 * 10^-19 Coulombs or whatever (this may not be accurate; I don't exactly know the elementary charge off the top of my head) then you can just plug those in... This help any?
  4. Apr 6, 2010 #3
    Coloumbs law can be also be written as [tex]F = qE[/tex].

    You are given for the value of the electric field strength and charge of the electron is known to be -1.602e-19 C. Now you can calculate for the electric force exerted on the charge by the field.
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