A magnet of mass 0.05 kg is dropped and falls vertically. It then enters at the top of a 25.0 cm copper tube. The speed when it enters is 1.50 m/s. Eddy currents are induced, causing the copper to warm up as the magnet falls through the tube. The speed of the magnet as it emerges from the tube is 1.50 m/s, the same as the initial speed. How much heat energy is dissipated to the environment?