When a bar magnet is thrust into a solenoid of copper wire that carries no current, the solenoid tends to:

repel the magnet

Explanation:

A solenoid is portion of wire which is made into coil shape cylindrical piece. It is an electromagnet. A bar magnet is a magnet which is in a bar shaped stick or slab. When bar magnet is thrusted into the solenoid which is of copper wire and carries no current, the solenoid tends to repel the bar magnet as the the current is induced in the solenoid of copper wire due to the bar magnet.

A change in kinetic energy occurs. Work = change in Kinetic Energy. Because friction acts in the opposite direction of the motion of an object, kinetic energy must be decreased in order to maintain the above equation. Friction opposes motion.