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Homework Help: Force on an electron in magnetic field:

  1. Mar 22, 2010 #1
    Q:What is the force on an electron that has a velocity equal to 2e6 m/s i - 3e6 m/s when it is in a region with a magnetic field given by 0.75 T i + 0.45 T j - 0.60 T k?

    F=q(v X B)

    I took the determinate of the electron's velocity and magnetic field and came up with <1.8e6,1.2e6,3.15e6> then multiplied my answer by 1.6e-19 C. My final answer is <28.8,19.2,50.4>pN.

    Did I miscalculate anything?
  2. jcsd
  3. Mar 23, 2010 #2

    Filip Larsen

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    Gold Member

    Assuming the -3e6 m/s speed component is along j, I get same result as you for vXB, but for the force you may want to check the magnitude of you result (I get 0.28 pN for first component). The problem text didn't mention if the result should be specified as a vector or as a magnitude (i.e. |F|), so it would probably be nice touch to include both in your answer.
  4. Mar 23, 2010 #3
    The answer is asked to be given as a vector.
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