9. A group in class suggests a model of magnetism in which an unrubbed iron nail contains a large number of separate N and S entities randomly arranged. When a magnet is rubbed from one end of the nail to the other, their model says that the entities re-distribute themselves according to the following diagram: Magnetized Nail SNSNSNSNSNSN SNSNSNSNSNSN Consider the following three observations that could be made with a magnet-rubbed nail: When one end of a magnetized nail is brought near the rubbed nail, it attracts one end of the nail and repels the other end. II. When the rubbed nail is cut in three equal-length pieces, each of the