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Homework Help: Qvxb maybe not?

  1. Apr 11, 2009 #1
    qvxb maybe not??

    1. The problem statement, all variables and given/known data
    consider the example of a positive charge moving in the -z direction with speed with the local magnetic field of magnitude in the +z direction. Find , the magnitude of the magnetic force acting on the particle.
    Express your answer in terms of , , , and other quantities given in the problem statement.

    2. Relevant equations

    f=qvXb yet this does not work ;/
    This would be true if and were orthogonal. Instead, they are antiparallel--look back at the definition of the cross product if you still have trouble.
    3. The attempt at a solution
  2. jcsd
  3. Apr 11, 2009 #2

    Doc Al

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    Staff: Mentor

    Re: qvxb maybe not??

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

    works just fine, but that only equals qvB when v and B are orthogonal.
    Sounds like good advice to me.
  4. Apr 11, 2009 #3
    Re: qvxb maybe not??

    thank these things just confuse me at time :) lol easy to study for hard to do some how :/
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