Let me answer it in a slightly different way.
If you have a coil facing a north pole of a magnet and the attractive force is 200N then reversing the current in the coil will cause a repulsive force of equal magnitude provided that the molecules in the magnet to no change position. Now here is the twist. In an iron magnet the molecules do change position and you will not get a repulsive force of equal magnitude. In fact the coil may still attract the magnet and your iron magnet will become remagnetized in the opposite direction.
Think of it this way. An iron magnet is actually comprised of a whole lot of little electromagnets because the iron particles are atoms with electrons orbiting around them. And the direction of this orbit can be altered thereby shifting the entire orientation of the iron molecule by subjecting the molecule by a very strong external magnetic field. In fact this is how some permanent magnets are made.
Magnetism is simply the relativistic affect of a moving electric charge as explained by Albert Einstein in his special theory of relativity.
Initially I was not in agreement with your friend until I considered replacing one of the magnets with an equal weight/size iron bar. It will be attracted by either pole of the magnet but not repulsed. Can you surmise where I'm going with this?
CYA: On the other hand I might be all wet!
Chris
Thank you John,Chris
I think of it in terms of logic, if you have an electromagnet that has two poles, everything is equal between the poles. The North pole = The S pole, thus the force is equal.
I never heard of a dipole having different factors in their poles that would lead to them being non-equal.
So logically when the electromagnet attracts the magnet(Neodymium) at 200N of force, if I switch the current the other way around I believe the magnet well be repelled at the same rate of force attracting it.
Hope that makes sense...
But I tired understand you points of view but its not giving me a proper kick in the noggin.
The thing is, I have no evidence to prove my point. Other than common sense
What do you all think?