I have two bar magnets (actually stacks of small magnets, but I believe they should behave the same) attached to a stack of (presumably conductive) coins, and not diametrically opposite. When I rotate one bar, the coins rotate based on height (corresponding to the rotation on the part of the magnet they are touching) and the second bar magnet rotates in the same direction as the first. However, the magnets also move around the stack of coins towards each other, which I can't explain. This occurs regardless of the direction of rotation or which magnet is being rotated, etc..

When the magnets start opposite each other, this does not occur.

EDIT: if instead force is applied only to the top coin while the bottom one is held still, the same occurs.

  • $\begingroup$ if you do not rotate but just touch the magnets to the coins, do they stay at rest or go towards each other? from the poles you draw there should be attractive forces. $\endgroup$ – anna v Apr 20 '19 at 6:09
  • $\begingroup$ They stay at rest. $\endgroup$ – The Zach Man Apr 20 '19 at 15:15

This is on the ground I assume, not in the air. You are holding the magnet on the right side.

When the magnet on the left rotates, it is also acting as a wheel, since it is round and it is rolling on the ground towards the right side, where the other magnet is.

Now you could ask, ok, but why does then the magnet on the right not roll towards the right too, so away from the magnet on the left? Because you are holding the magnet on the right with your hand, as you rotate it, it cannot move relative to the starting position.

If you could somehow try to do this in the air, the magnets would not move closer to each other, since the magnet on the left would have nothing to roll on.

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  • $\begingroup$ This doesn't seem to be the case - it happens on the ground, it happens in the air, it happens when I support only the coins. $\endgroup$ – The Zach Man Apr 20 '19 at 15:16

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