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Electric field of a point charge in uniform motion

  1. Dec 25, 2013 #1
    In Griffiths Chapter 12, pg 527:

    Suppose a point charge is moving along x, we obtain the following E-fields:


    1. Is the vector R solely in the x-y plane?

    2. What happened to the coordinate 'z' ?

    3. Why are they only doing things in the 2-D plane? Can we use rotational symmetry somewhere?

    Last edited: Dec 25, 2013
  2. jcsd
  3. Dec 25, 2013 #2
    When instead, I assume the particle to be moving along z-axis it fixes everything!

    and i use x=Rsinθcosø, y = Rsinθsinø, z = R cos ø

    The end result turns out beautifully to be the one as described, in 3 dimensions:


    I suspect that since Polar coordinates is usually defined with θ as angle between R and z-axis and ø as angle in x-y plane, everything matches.
  4. Dec 29, 2013 #3
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