You have two identical looking metal bars. One of them is a magnet, with North and South ends. The other is simply an iron bar (which is attracted by magnets).

How can you tell which is which, using only these two bars?

(In reply to Reply to John by Penny)

*flexes* Yes, I'm always eager to find the brute force solution, if there is one. ;-)

Seriously though, how would you know which was the bar which had been newly magnetized?  Since the bars behave the same way toward each other before and after the magnetization of one of them, I'm not sure how you're making that distinction in the first place.

Are you saying the bars can be rubbed together in such a way that if Bar A is the magnet it will magnetize bar B, but if bar B is the magnet it will not magnetize bar A?

Posted by John on 2005-01-25 17:08:36