If you were to drop a bar magnet from 3 meters off the ground and measure the time that it took for the magnet to fall, an dthen dropped the same magnet from 3 meters off the ground through along copper tube and measured the time that it took for the magnet to fall, would the two times be the same? Explain why or why not.
No. The magnet falling through the copper tube would fall slower. Because another force acts on it, and I am not talking about friction. The force I am talking about, is the force of the magnetic field of the induced circulating current in the copper tube sections. The falling magnet is changing the magnetic flux inside the tube, which, as per Faraday's law of induction, will induce a voltage around the loop of tube section, and in turn, will cause a circulating current. There then is a magnetic field created by the circulating current, which, if you work out the directions carefully with the proper hand rules, you will see it will exert a force upward on the falling magnet. You can also know this force to be upward, with a conservation of energy argument. Had you suggested a pipe of plastic (or something else that is an electrical insulator), then they would fall at the same rate (disregarding the nearly non-existent friction).
