Question

A magnet hanging from a spring bounces in and out of a metal ring. Although it doesn't touch the ring, the magnet's bounce diminishes faster than it would if the ring weren't there. Explain.

Answer 1

Magnetic damping due to eddy currents induced in the metal ring causes the magnet's bounce to diminish faster than in the absence of the ring.

Step-by-step explanation:

When a magnet hanging from a spring bounces in and out of a metal ring, the bounce diminishes faster than it would if the ring were not there due to the principle of magnetic damping. This effect is caused by eddy currents, which are loops of electrical current induced within conductors by a changing magnetic field in the conductor, according to Faraday's law of electromagnetic induction. As the magnet moves, its magnetic field changes, which induces these eddy currents in the surrounding metal ring. These currents, in turn, generate their own magnetic fields that oppose the change in the initial magnetic field of the magnet as described by Lenz's Law, thus creating a drag force. This force acts against the motion of the magnet, causing it to slow down more rapidly than it would in the absence of the metal ring.