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When you place two magnets with opposite poles facing eachother vertically they attract. However if you move one magnet horizontally by a distance greater than the magnets diameter they will begin to repel in the vertical direction but still maintain attraction in the horizontal direction. Why is this?

(Note: first, the nessesary horizontal displacement for vertical repulsion is a rough estimate. I am using my hands to measure force so I can really only measure up to 7cm. Second, the direction I chose to place the magnets is arbitrary.)

Edit: (Sorry, I can't include a picture because the file is too large. I will try to describe situation in more detail below:

Case 1: imagine two magnets aligned vertically with opposite poles facing eachother separated by some distance. In this case the two magnets will attract

Case 2: now imagin the same set up as case one but move one of the magnets to the side by a distance of atleast the magnets diameter. In this case the magnets repel in the vertical direction.

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  • $\begingroup$ Can you possibly draw a diagram to more clearly illastrate the situation? $\endgroup$ May 25, 2022 at 22:17
  • $\begingroup$ "oposite" is not a word. $\endgroup$
    – hft
    May 25, 2022 at 23:12

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Something to remember is the magnets are not really trying to attract or repel, they are trying to get their fields to align. The photo

photo

shows this field. If the magnets are stacked vertically north to south, the field arrows line up perfectly (the ones exiting the top of the lower magnet enter the bottom of the upper magnet, go through it on its axis, and exit out the top), and it wants to stay that way. If you start sliding the magnets around, the sets of field lines change direction as shown. What the magnets will seek is a state where the arrows from both fields point in the same direction at any given point, and this may cause the bar magnets to spin or resist in unpredictable ways. It is not as simple as "attract" or "repel."

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  • $\begingroup$ Thank you, I think I have a better understanding now but I'd like you to poke holes in it if I'm wrong ( only if you have time) After drawing the field lines for the two scenarios I can see in the case where they are lined up the field lines can flow through both magnets adding together as if they were just one magnet resulting in a lower energy. When the magnets are offset by atleast its diameter this is no longer possible and there are places where the field lines cross eachother resulting in a higher energy. Here the magnet is pulled horizontally inorder to reach a lower energy state. $\endgroup$
    – Matthew
    May 25, 2022 at 23:40
  • $\begingroup$ Yes. Although it's not really the field lines crossing that's the issue. At any point in space you will have two field arrows, one contribution from each magnet. If those two arrows are any orientation other than aligned, there will be a force trying to make them align $\endgroup$
    – RC_23
    May 25, 2022 at 23:53

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