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Can repulsing magnets create lift?

  1. Dec 27, 2014 #1
    Suppose there are 2 sets of magnets housed inside a box.One set can move vertically and the other set moves horizontally.Now if enough repulsion is created between the vertical set's magnets the top magnet will touch the box's body and try to go out but can't.So if I keep the repulsion going will the top magnet create a force enough to lift the whole box up in air and keep going?

    Can the same happen for the horizontal set's magnets to move left and right?

    Here is an image:

    v9ZPk1z.png
     
  2. jcsd
  3. Dec 27, 2014 #2

    mfb

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    That will work until the lower magnet hits the box as well (or gets so far away the force becomes negligible), so the best you can get is a tiny "hop" until you support the lower magnet externally (then you reproduce the idea of a maglev train).
     
  4. Dec 27, 2014 #3
    I was thinking of using hydraulics to move the lower magnet up and down or hold it at a certain position to create the repulsion.

    I am trying to find out what kind of magnets will I need to make this happen properly.I need to keep the craft as light weight as possible.Do you think electro magnets are a good idea?
     
  5. Dec 27, 2014 #4

    mfb

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    No matter what you do, if you do it within the box you do not gain anything as the repulsion between the magnets gives the same force (just in opposite direction) on both sides.
    The type of magnet does not matter, the basic idea has a fundamental flaw and cannot work at all.
     
  6. Dec 27, 2014 #5
    Could you tell me what the fundamental flaw is?

    What if the lower magnet is more stronger compared to the upper one.So the repulsion won't be the same right?
     
  7. Dec 27, 2014 #6

    mfb

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    Newton's third law. Or, more general, conservation of momentum.
    It will be exactly the same. No matter which magnets you use, how you put them in and so on.
     
  8. Dec 28, 2014 #7
    Suppose there are 2 sets of magnets housed inside a box.One set can move vertically and the other set moves horizontally.Now if enough repulsion is created between the vertical set's magnets the top magnet will touch the box's body and try to go out but can't.So if I keep the repulsion going will the top magnet create a force enough to lift the whole box up in air and keep going?

    Can the same happen for the horizontal set's magnets to move left and right?

    Here is an image:

    v9ZPk1z.png
     
  9. Dec 28, 2014 #8

    jtbell

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    Can you lift yourself up into the air by pulling on your own bootstraps?
     
  10. Dec 28, 2014 #9
    Bootstraps don't repulse.
     
  11. Dec 28, 2014 #10

    jtbell

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    OK, strap a rigid hat firmly onto your head. Can you lift yourself into the air by pushing upwards on the brim of the hat? :)

    That's basically the same thing your two magnets are doing: pushing on each other.
     
  12. Dec 28, 2014 #11
    Maybe I could if the force is strong enough.And I mean really strong.

    I just want to know what kind of magnets I need and what calculat6ions should I be doing to make a good assumption.
     
  13. Dec 28, 2014 #12

    Doug Huffman

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    Where's the Earth shattering KABOOM! on loss of the Third Law?
     
  14. Dec 28, 2014 #13
    Tell me one thing about Newton's third law.If one object is big and the other is small and they collide with each other,will the smaller object react with the same force that was applied to it by the bigger object?
     
  15. Dec 28, 2014 #14

    mfb

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    Yes.

    Sorry, we cannot help you violate the laws of the universe. It is impossible, no matter how hard you try. I closed the thread.
    Please do not open multiple threads for the same topic.
     
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