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Homework Help: How are magnets able to attract each other?

  1. Feb 1, 2013 #1
    1. The problem statement, all variables and given/known data
    As magnets have two poles, when i place two bar magnets together with opposite poles facing each other besides the two opposite poles attracting each other will the north and south pole on one magnet repel the north and south pole respectively?

    2. Relevant equations
    none that i have heard of

    3. The attempt at a solution
    According to this post i found on reddit: http://www.reddit.com/r/askscience/comments/17hit9/why_can_there_be_attraction/c85qet6 there won't be any repulsion as the magnetic field is 'combined' together. So we cannot use http://www.reddit.com/r/askscience/comments/17hit9/why_can_there_be_attraction/c85jt4i to calculate the attraction.

    However, I sort of disagree with that as polarized metal objects also have a similar electric field which combines as well http://ars.els-cdn.com/content/image/1-s2.0-S1569441012000624-gr2.jpg while in this situation we still use Coulomb's Law to find out the net force acting on the various object.

    Can someone clear up this misconception? Thanks for the help :)
  2. jcsd
  3. Feb 1, 2013 #2


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    2017 Award

    Staff: Mentor

    There are no regions "north pole", or "south pole", the colors/marks on the magnets are a bit misleading in that respect. Try to separate north and south pole of a magnet: You will get two smaller magnets which have a magnetic field similar to the original one.

    You can approximate the field of a magnet with hypothetical poles with a magnetic charge - in that case, yes, the S poles from both magnets would repel each other (+the same for N of course), but the force between S and N and N and S would be stronger.
  4. Feb 1, 2013 #3
    Oh the diagram I found was for the polarized metal http://www.sciencedirect.com/science/article/pii/S1569441012000624

    So what first link said was wrong?
  5. Feb 2, 2013 #4


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    Homework Helper

    Not only an answer can be wrong... There are wrong questions. The magnets attract or repulse. When you say that the magnetic "poles" attract or repel you have to ask yourself "What is magnetic pole at all? "

    The question in the title of the thread "How are magnets able to attract each other?" can be best answered by Feynman: They just do. It is the nature of the magnets.

    Watch the video "Richard Feynman. Why."

  6. Feb 2, 2013 #5
    Re: Re: How are magnets able to attract each other?

    The same video was shown in the reddit comments. 2 last questions before I drop this problem, when the magnets attract, is there any repulsion between the like poles present? And if not why won't there be the repulsion since shouldn't it be similar to an electric field?

    Thanks for the help :)
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