Physics: Principles and Problems

Chapter 24: Magnetic Fields

Problem of the Week

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Electron Magnetism
In Chapter 24, you learned that electrons have magnetic fields. Because all matter contains electrons, all materials including living things have a magnetic field. This magnetic field is very weak and usually remains unnoticed in everyday life. Make a large enough magnet, however, and the effects of electron magnetism start to be seen.
The ability to levitate does not depend on the amount of material involved. A large object has proportionally more "electron-magnets" to counteract the increase in mass.

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"Float" a Frog
<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::::/sites/dl/free/0078458137/193800/ch24_frogFloater.jpg','popWin', 'width=NaN,height=NaN,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (9.0K)</a> To "float" a frog, acquire a 16-Tesla magnetic field and one frog. The electrons spinning inside each atom of the frog will give each atom a magnetic field of approximately 2 x 10-4 T.

The 16-T super magnet will push against all the little electron magnets and the frog will overcome the constraints of gravity. Not only can frogs be levitated, you too can be suspended above the ground. And because each atom in your body has the gravitational force counterbalanced by the magnetic force, you will feel totally weightless, as if you're in outer space.

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