so in my physics class today we were discussing solonoids and toroids. if the solonoid or toroid is producing a magnetic (B) field inside its tubular structure, why could one not use it to move an object which responds to magnets? I asked my professor and he said that a B field cannot be used to accelerate an object, only to deflect its path. So I started wondering, why then if you put two magnets close together do they pull eachother into contact with one another? It makes sense in my head that if you were to put a small magnet in the B field produced inside one of these objects such that the north end of the small magnet faced the south end of the toroid/solonoid and the south end toward the north, the little magnet could be propelled through the solonoid/toroid. I suppose I have this fantasy of somehow finding a way to almost entirely neglect friction and make a transportation divice out of an enormous toroid which would act like a subway, and the wheels would act like alternators charging up huge capacitors which could run the toroid such that it would require little extra energy to be put into the system so it would almost be self-sufficient. we don't need to go into the physics of that, b/c it's just way too in depth. however, why can you not propel an object through a solonoid or indefinitely inside a toroid? Why can a B field not accelerate an object?