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Formulating Lorentz's force law

  1. Mar 5, 2006 #1
    How did sir Hendric Antoon Lorentz got to his formula:
    F= B v q

    Was i just experimental? or is this something witch follows out of the maxwell equesions or wath?
  2. jcsd
  3. Mar 6, 2006 #2


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    You mean

    [tex] \vec{F}=q \vec{v}\times\vec{B} [/tex]

    ,surely. I dunno the answer to the first question, but i do for the second. It follows in relativistic electrodynamics as a motion equation for a relativistic electrically charged particle in an electromagnetic field. Such equation can be derived as the Euler-Lagrange equation for the action obtained by adding the action for a free particle and the interaction term.

  4. Mar 6, 2006 #3


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    Without invoking the action principle, yeah it's a fundamental axiom of the theory of EM and its justification is certainly experimental. Turns out that in relativity, Maxwell's equations don't need changing, but the Lorentz force law does.
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