Experiment: How copper and magnet interact
For the experiment, you will need only two things - this is a neodymium magnet (preferably a cylindrical magnet) and an ordinary metal pipe made of a non-magnetic material, such as copper. The internal diameter of the pipe should be slightly larger (say, one and a half to two times) than the external diameter of the magnet. Well, now try to just drop the magnet on the floor - for the first time outside the pipe.
If you are not growing with Uncle Stepa, then after about half a second you will hear a characteristic magnet knock on the floor (and if you are still an uncle, you will need 0.1 second more). Now lift the magnet off the floor and drop it inside a vertically oriented pipe. And while you wait for the magnet to appear from the lower section of a completely non-magnetic (but necessarily conductive!) Pipe, let us try to explain why this takes so much time.
By the way, you can look into the pipe through the upper end - is there a magnet stuck there? No, not stuck - he just falls very slowly.The reason for this is the inextricable link between magnetism and electricity. The movement of the magnet generates a change in the magnetic field, which, in turn, induces circulating circular currents in the tube.
And these currents generate magnetic fields that interact with the field of the magnet, slowing its fall. Well, now you know the reason and can show your friends a spectacular trick. More precisely, you can do it when the magnet finally flies through the tube.