Magnets and Fall
There are two cylindrical slugs of metal were allowed to free-fall
down a hollow vertical tube made of copper. One of the slugs, a magnet, took
significantly longer to fall through the tube than the other.
A changing magnetic field induces an electric field in a conductor. This
new changing electric field induces a changing magnetic field, etc. Energy
is being transfered from the gravitational field to the kinetic energy of
the falling magnet. Some of this kinetic energy is transferred into the
generated electric field. Since some of the kinetic energy is transferred,
the magnet does not accelerate as it normally would when falling freely in
a gravitational field.
There is more information on this subject. Use 'eddy currents' as your
---Nathan A. Unterman
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Update: June 2012