Hello everyone, I was studying for my electromagnetism test by doing questions from a text book that I won at the university's open house. This means that I don't have the complete answer key and neighter does my physics teacher. While reading through it, I came upon an interesting question. Here it is: I can't seem to figure it out and I even asked my physics teacher for help. Some theories that we came up with are that you could hit one bar with the other and split it in half, and then see if both halves of the split bar will attract/repel. The problem with this is that the impact could cause the pernament magnet to demagnetize and it might be quite hard to hit them against each outher so they split. Another theory we came up with is that you could balance one on the corner of other and see if it turns toward the earth's magnetic poles (this is just like hanging it from the ceiling with a string), but then to balance it perfectly would be very complicated. Does anyone have any idea how this problem could be solved? Or have the answer key to College Physics by Wilson and Buffa (4th Edition)? It is question #4 from chapter 19 in that book.