Final answer:
The bottom of the last paperclip hanging from the north side of a bar magnet will present a north magnetic pole. This demonstrates how magnets induce opposite poles at the ends of ferromagnetic materials.
Step-by-step explanation:
When three paperclips are hanging from the north side of a bar magnet, they take on the properties of the magnet itself due to the magnetic field. The bottom of the last paperclip, being furthest away from the bar magnet, will present a north magnetic pole. This is because in a chain of magnets or magnetic objects, the opposite pole from the one at the point of contact is induced at the other end. This phenomenon is consistent with the law of magnetic poles, which states that opposite poles attract and like poles repel each other. Since the first paperclip is attracted and connected to the north pole of the bar magnet, it must have a south pole at the point of contact and a north pole at its opposite end. The subsequent paperclip will then have a south pole at the contact point with the first paperclip's north pole, and so on.
Furthermore, this question highlights a fundamental principle in magnetism: every magnet has a north and a south pole, and these poles cannot be isolated. This principle is derived from the characteristic of magnets always being magnetic dipoles, which means they have two opposite poles that cannot exist separately. If you were to cut a magnet in half, each piece would still have a north and a south pole.