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Homework Help: Metalrod and magnetic field

  1. Feb 15, 2007 #1
    1. The problem statement, all variables and given/known data
    mass=m
    length=l
    initialspeed=v0
    magneticfield=B
    Resistor=R

    2. Relevant equations
    A metal rod of mass m and length l slides on two parallell frictionless rails.
    A uniform magnetic field is directed perpendicular to the plane of the rails.
    There is no external agent applying a force to the rod.

    Show that v(t) = v0e^t/T
    where T = mR/(Bl)²

    3. The attempt at a solution

    I dont know where to start. Shall I construct a differentialequation including dt and dA? If not the solution I would be greatful for some hints.
     
  2. jcsd
  3. Feb 15, 2007 #2

    siddharth

    User Avatar
    Homework Helper
    Gold Member

    Do you realize that there will be a motional emf developed? If find that, you'll be able to describe the motion of the metal rod.

    This link should help
    http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elevol.html#c3
     
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