I been having trouble lately with my phyiscs HW probs. Here is only that ti'm confused on: Three wires are connected to form a vertical H. The cross piece, mass 0.050 kg and length 0.10m , can slide up and down the vertical wires without friction. The device is placed in a horizontal field that varies B=0.10y where y is the vertical distance from the bottom of the H. What current in the H is required to lift the cross piece .05m MY q's: Is this a magnetism prob? (thats what we are learning in class) also can i make the cross piece effectively start from the bottom? Must I incorporate gravity?