Our professor did a demonstration today for our physics II class. She was demonstrating electromagnetic induction with a solenoid and a metal ring. When she slid the ring down the solenoid and passed alternating current through the solenoid, the metal ring was flung upward off the solenoid. My professor was attempting to demonstrate magnetic induction but she never explained the net upward force. I get that currents are induced and the resulting field opposes the original field, but why in the upward direction? why not downward?