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Are two magnets twice as strong as one?

  1. Mar 23, 2012 #1
    Hi there,

    I am having trouble with a project I am working on... hopefully someone will be able to help me. :)

    I have some neodymium magnets that are rated as having a ”pull" strength of 3.1kg each, I am assuming that this means that you can attach it to a metallic surface and it would take 3.1kg (or about 30N) to pull it off.

    If I was to attach one magnet to another, and try and pull them apart, would they pull towards each other with 30N of force each, resulting in 60N being required to pull them apart?

    I have done some testing with a tensile testing machine, and the results have confused me somewhat, the two magnets separated at 24N. I have come to the conclusion that either I am hideously wrong in my assumption and have now got to rectify my mistake, or the manufacturer has been somewhat generous with their quotes.

    I've spent some time looking online and I cannot seem to find an answer to this, so if anyone is able to help I would be grateful: D
  2. jcsd
  3. Mar 23, 2012 #2
    Well, there's a simple way to test this, isn't there? :wink: Next time, use a single magnet attached to a static object, and measure the amount of force. If it's not more or less equal to 12N (you can measure that one again if you want to), then no, attaching those two magnets together doesn't require twice the force to separate. :smile:
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