A steel clip is not a magnet. What can a magnet do to the clip?
In a drawer sits an unlabeled steel bar. It might be a magnet. It might be plain steel. A second, labeled magnet can settle it.
The last lesson drew the line: two magnets can attract or repel, but a magnetic material can only be attracted. That one-sidedness is the test.
Bring one pole of the known magnet toward one end of the mystery bar, and watch.
Suppose the end swings away: the bar repels the known pole. Only a magnet can repel. So the bar is a magnet.
Now suppose the end is attracted toward the known magnet instead. A magnet attracts the unlike pole of another magnet. A magnet also attracts any magnetic material. So attraction cannot tell the two apart. The bar could be a magnet, or just a magnetic material.
One pole of a known magnet repels a metal bar's end. What is the bar?
Omar brings a known magnet's N pole toward an unlabeled metal rod. The rod's end swings away. What is the rod?
The rod repels the known magnet's pole.
Only a magnet can repel.
The rod is a magnet.
A kitchen knife's steel blade clings to a known magnet. Does this prove the blade is a magnet?
The blade is attracted to the known magnet.
A magnet attracts unlike poles of other magnets, and it also attracts any magnetic material.
So attraction alone cannot tell which one the blade is.
No. The blade could be a magnet, or just a magnetic material.
Jude says a bar that clings to a known magnet must itself be a magnet. Is Jude correct?
Petra says an object that repels one pole of a known magnet must itself be a magnet. Is Petra correct?
Hana tests an unlabeled bar from a garage shelf with a known magnet's S pole. The bar's end pushes away. What is the bar?
A metal rod in a toolbox is attracted to a known magnet. Attraction cannot settle what the rod is. Why?
Which observation proves that an object is a magnet?