Why a perpetual magnet engines do not work?

Question

A sample of this motor:

[https://www.youtube.com/watch?v=LXBYMiNH1nE](https://www.youtube.com/watch?v=LXBYMiNH1nE)

In: 87

Answer 1

Think of magnets like hills. You can roll a tire down a hill to gain momentum, but it loses it when rolling up the next hill. You can’t arrange a series of hills in such a way, that a tire both gains speed and at the end is back to the baseline height. (You can throw a tire down a well, it will go superfast, but it will end up at the bottom of a well, which isn’t useful)

Magnets have a potential around them, just like hills – you can use that once to do something when you are on top, but you can’t roll down the same hill twice. The potential alone can’t add energy to the system.