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Homework Help: Acceleration of magnet

  1. Nov 15, 2012 #1
    1. The problem statement, all variables and given/known data
    A magnet is dropped towards a loop of copper .the acceleration of magnet will be ?

    2. Relevant equations

    3. The attempt at a solution

    less than g ,because copper will oppose the relevant pole(im not sure why?)
  2. jcsd
  3. Nov 15, 2012 #2
    Lenz's law
  4. Nov 15, 2012 #3
    cant really understand it.. can u explain it?
  5. Nov 15, 2012 #4
    Acceleration of a magnet? Interesting question, I would like to hear more.
  6. Nov 15, 2012 #5
    what do you know about copper?

    it is conductive and non-magnetic material.

    if it has no magnetic attraction , then what is the force that acts on the magnet ?

    this is when the LENZ's law comes in,

    for your case , magnetic fields dropped through the copper loop (conductor) and induces electrical current, current in the conductor then generates an opposing magnetic field that causes "less than g" :-)

    do you know what is eddy current?
    Last edited: Nov 15, 2012
  7. Nov 15, 2012 #6
    The changing magnetic flux will produce and emf in it. This will produce a current in the loop. Lenz's law state that the direction of the current will be such that the magnetic field that it produces will oppose the original magnetic flux that induced the emf.
  8. Nov 15, 2012 #7
    Got it thanks. Induced emf, neat.
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