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Homework Help: Help with electron in electric field problem!

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

    An electron has an initial velocity of 5 ×
    105 m/s in the x direction. It enters a uni-
    form electric field ~E = (440 N/C) ˆj which is
    in the y direction.
    The charge and mass of an electron are
    1.6×10−19 C and 9.11×10−31 kg, respectively.
    Find the acceleration of the electron.
    Answer in units of m/s2.

    2. Relevant equations

    F=eq
    F=ma


    3. The attempt at a solution

    I tried using those two equations and coming up with a = Eq/m, but thats not the correct answer!
     
  2. jcsd
  3. Jan 6, 2010 #2

    Doc Al

    User Avatar

    Staff: Mentor

    That should work just fine. Show what you did.

    Since acceleration is a vector, they may want you to specify its direction as well.
     
  4. Jan 6, 2010 #3
    440 * (1.6e-19)/ (9.11e-31) = 7.2777e13 m/s^2

    I'm submitting it into an electronic homework service, which is very picky. I tried submitting a negative answer too, but thats is not correct either....
     
  5. Jan 6, 2010 #4

    Doc Al

    User Avatar

    Staff: Mentor

    Check your arithmetic. (I suspect it's just a typo here.)

    Since the directions were given using unit vectors, perhaps that's what they want in the answer.
     
  6. Jan 6, 2010 #5
     
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