i am having a few problems with a project im doing for university. The basics of which are force/energy/field size needed to lift magnets. Basically, i need to show some calculations for the repulsion/attraction forces etc and my knowledge on electromangetism is limited. For the first system of electromangetic attraction (EMS maglev suspension) we have a mass(train) being suspended above a track and the vehicle curls round the track. Under the track the electromagnet on the train is attracted to a permanent magnet. I have tried to get some equations relating the field strength, current, turns in the wire etc but just cant seem to get any equations right. also, there is a repulsive system (EDS) whereby an electromagnet (usually a superconductor) is above a track on a train and induces currents in the track that repel the train. I cant figure out and sort of equation for the field strength, energy used or force required to left the train here either. Could someone please help me out.