A bar magnet is released from rest along the axis of a very long vertical copper tube. After some time the magnet will

The flux connected to the copper tube will fluctuate when the magnet moves under the influence of gravity. Eddy currents will be created in the copper tube's body as a result, these induced currents oppose the collapse of the magnet, in accordance with Lenz's law.

A retarding force will consequently act on the magnet. This force will keep rising with the magnet's rising velocity until it equals the force of gravity. The net force acting on the magnet will then vanish. The magnet will therefore reach a steady speed.