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Homework Help: Ambient Electric Fields.

  1. Jun 4, 2009 #1
    Sorry if i have posted under the wrong catagorie physics is new to me so im still getting my head around it.

    Here is the question that is giving me a bit of bother;
    An airplane is flying through a thunder cloud at an altitude of 2km. If the cloud has a charge concentration of 40C at an altitude of 3km above the ground and -40C at 1km altitude. What is the ambient electric field exsperienced by the air craft?
    Additional information k = 9 x 10^9 N-m/C^2)

    so far i have think the equations to be used are F=kQ,Q2 / r^2

    this is what i get when i fill the following information = (9*10^9)*(40)*(-40) / 1^2

    this equaling -1.44^13
    Am i going the right way about it or have i missed a few steps? any guidance would greatly be appreciated.
  2. jcsd
  3. Jun 4, 2009 #2


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    Homework Helper

    Convert kilometer to meter.
  4. Jun 4, 2009 #3
    After changing the km into meters

    (9*10^9) * (40) * (-40) / 1000^2

    this gave me answer of = - 14400000
    this answer seems a little big. or is it meant to be this large?
  5. Jun 4, 2009 #4
    Hmm 40C is wayyy too big. But anyways, your not answering the question. What is the electric field experienced by the plane question mark. (Sorry keyboard problems)
  6. Jun 6, 2009 #5
    Not sure if I can help at all, I'm stuck in the same place. I think we are studdying the same thing.
  7. Jun 6, 2009 #6
    Just found this, hope it helps:

    See attachment, it didn't want to past in here.

    Edit: Note the diference in k from your origional question.

    Attached Files:

    Last edited: Jun 6, 2009
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