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Homework Help: Electric Field & Capcitor Problem HELP

  1. Jul 5, 2007 #1
    Electric Field & Capcitor Problem HELP!!

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

    An electron enters the lower left side of a parallel plate capacitor & exits at the upper right side making an upward curve. The initial speed of the electron is 4.00 x 10^6 m/s. The capacitor is 2.00 cm long, and its plates are separated by 0.150 cm. Assume that the electric field between the plates is uniform everywhere and find its magnitude.

    3. The attempt at a solution

    So I understand that F=ma=qE. I also understand that I can use kinematics to find the acceleration and I can also use the mass of an electron to figure out the force. However, how do I find q? I'm so confused!!!:confused: Please help! Thanks!!
  2. jcsd
  3. Jul 5, 2007 #2


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    q is the charge of the electron. You don't compute it, you look it up. -1.6*10^(-19) coulombs.
  4. Jul 5, 2007 #3
    Thank you so much!!! That's great...duh.
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