Beeroome

Hello. So let's say we have setup (simplified) consisting of a metal rod or cylinder, inside a long tube. Surrounding the tube are magnetic rings of varying strength. The rings are placed in order of strength starting with the weakest, finishing with the strongest. I understand that the spaces if any, between them determine the distance at which the rod is attracted to each ring, but if we insert the rod into the tube and it accelerates, creating momentum, could the rings maintain, and due to strength variations increase the speed at which the rod is travelling? The benefit of rings would be that the attraction would be evenly distributed thus the rod would levitate, greatly reducing friction. Credit etc to MagLev etc who coined that theory obviously that's not the bit I wanted to ask about. I'm missing something I know, but I don't see why this principle isn't being utilised. It may be somewhere, if so help me out! I just want to know if this simplified idea would work for example if applied to projectiles, ballistics, travel just acceleration. Thanks. Forgive the probable lack of clarity here or there, I'm happy to clean up sections.