Like poles repel, unlike poles attract. I have noticed that, say, using a strong bar magnet's north pole pointing near to a weak bar magnet's north pole there is indeed a repel action. But as the two get closer and closer the strong magnet attracts the weak one and will hold onto it.It is as though the metal of the weak bar is 'more attractive' than the repel force?
Asked by Osiris2 17 months ago Similar questions: poles repel unlike attract Science > Physics.
Similar questions: poles repel unlike attract.
1 > But as the two get closer and closer the strong magnet attracts the weak one and will hold onto it. The north poles of two magnets always repel, regardless of their relative strengths. The north pole of the strong magnet will be attracted to the south pole of the other.
What usually happens is that the repulsive force between the two north poles eventually forces one magnet to physically flip around. Then the north side will be near the south side, and they'll happily snap together. If the north pole of the weak magnet is closer, then the repulsion force will always be stronger than the attraction to the other side.
The force is proportional to the inverse square of the distance; that is, if the south side is 3x further away, then the attraction will be 1/9th as strong as the repulsive side repels. There is an effect called a "phase change" where one magnet could induce the other magnet to flip polarity, but that's probably not what you're seeing in ordinary permanent magnets. It doesn't happen under circumstances you're likely to encounter.
But as the two get closer and closer the strong magnet attracts the weak one and will hold onto it. The north poles of two magnets always repel, regardless of their relative strengths. The north pole of the strong magnet will be attracted to the south pole of the other.
What usually happens is that the repulsive force between the two north poles eventually forces one magnet to physically flip around. Then the north side will be near the south side, and they'll happily snap together. If the north pole of the weak magnet is closer, then the repulsion force will always be stronger than the attraction to the other side.
The force is proportional to the inverse square of the distance; that is, if the south side is 3x further away, then the attraction will be 1/9th as strong as the repulsive side repels. There is an effect called a "phase change" where one magnet could induce the other magnet to flip polarity, but that's probably not what you're seeing in ordinary permanent magnets. It doesn't happen under circumstances you're likely to encounter.
2 Sorry PamPerdue- Not entirely with that. As the two magnets are brought together N to N they repel as expected. You can feel one wants to physically flip.
But if you restrain it the repulsion 'cancels' to where there is now attraction. They hold together. It seems two N poles are attracting.
The phase change you mentioned seems to be the reason? .
Sorry PamPerdue- Not entirely with that. As the two magnets are brought together N to N they repel as expected. You can feel one wants to physically flip.
But if you restrain it the repulsion 'cancels' to where there is now attraction. They hold together. It seems two N poles are attracting.
The phase change you mentioned seems to be the reason?
It's possible. If you have a piece of non-magnetized iron, a magnet will induce a magnetic field in it, which is why the iron is attracted to the magnet. I suppose that if the weak magnet is really weak, the powerful magnet would induce magnetism in it as if it were a piece of unmagnetized iron (in the opposite direction of its previous orientation).
I wouldn't have though it would happen with ordinary home magnets, but it seems the most likely answer.
JWTK replied to post #3: 4 Yes, that is what is happening. There is no phase change, just the induced magnetization overwhelming the remnant magnetization. Best understood by looking at a plot of the hysteresis loop showing the dependence of the magnetization on applied field, for example:
In this plot Br is the remanent magnetization (the field strength of a permanent magnet in the absence of an applied field) and Hc is the coercive force (the field requried to reverse the polarity).Yes, that is what is happening. There is no phase change, just the induced magnetization overwhelming the remnant magnetization. Best understood by looking at a plot of the hysteresis loop showing the dependence of the magnetization on applied field, for example:
In this plot Br is the remanent magnetization (the field strength of a permanent magnet in the absence of an applied field) and Hc is the coercive force (the field requried to reverse the polarity).I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.