If you place two magnetic objects close to each other, they will attract or repel depending on the position. Yet no energy is added to this system, so how is it possible?
Another example is a levitating magnet in a box. It fights against the force of gravity without any force put into the system itself.
Please explain
Best Answer
These cases have nothing to do with Newton's first law. Newton's first law is:
(It's stated in many ways. That's the phrasing used on Wikipedia)
Note that the first law says absolutely nothing about energy or what forces are allowed to be on the system. All it states is that if the sum of the forces on an object is 0, its velocity doesn't change.
Ignoring Newton's first law, here's the things you were asking about in your examples: