A magnet of mass 0.20 kg is dropped from rest and falls vertically through a 35.0 cm copper tube. Eddy currents are induced, causing the copper to warm up. The speed of the magnet as it emerges from the tube is 1.10 m/s. How much heat energy is dissipated to the environment?

0.58 J

Explanation:

We know that Total energy is conserved.

Initial Kinetic energy + Initial potential energy = final kinetic energy + final potential energy + dissipated heat energy

Initial kinetic energy = 0 (magnet is at rest initially)

Initial Potential energy = m g h = (0.20 kg) (9.81 m/s²) (0.35 m) = 0.69 J

Final kinetic energy = 0.5 m v² = 0.5 * 0.20 kg * 1.10 m/s = 0.11 J

Final potential energy = 0

∴ Dissipated heat energy = (0.69 - 0.11) J = 0.58 J