Eli5 how do copper and magnets interact?

Question

I recently saw this video of a magnet swung against a copper slab and the magnet stops right in front of it. What happens there? Why?

In: 1

Answer 1

Moving magnetic fields through a conductive object makes electricity. Moving electricity makes magnetic fields.

When you move a magnet close to a piece of copper, it moves the electrons in that copper around, making electricity. Since the magnetic field is moving, the electricity moves too, making its own magnetic field. [This magnetic field repels the magnet, creating a force that opposes the movement of the magnet.](https://en.wikipedia.org/wiki/Lenz%27s_law)

[The typical demonstration drops a magnet down a piece of copper tubing.](https://www.youtube.com/watch?v=H31K9qcmeMU)