Force and Induced EMF?

F=ma. Max speed means a =0. There must be an uphill force from EM induction, to balance normal force and gravity. The faster the bar goes, the faster the flux through the loop changes (loop made of bar, two rods, and resistor.) Voltage induced is change in flux over time. V=IR gives you the current in the bar. F=ILB gives the force. Flux is BAcos theta, or BLW cos 20. Flux over time is BW(L/t) cos 20, and L/t = v. I hope that is enough. Good luck!