Re: Teaching Magnetism

[Larry Cartwright <exit60@CABLESPEED.COM>]

John Clement wrote:
> The other problem that I see is that my bar magnets are very weak, but
> with the disk magnets it is harder to see where the poles are located.
> Also my bar magnets already have labels N on one end.

Anyone who uses old iron-alloy magnets (bars, horseshoes, etc) in their
instructional program should consider investing in a re-magnetizing
coil.  Those alloy bars probably didn't have much of a field when they
were new, and they get worse with time.  A re-magnetizer removes a lot
of the frustration which comes from trying to conduct experiments with
"magnets" that are not magnetic.

The "N"'s can be cut off or ground off some of the bars if you want an
unlabelled set.  If you have a re-magnetizer, you can make your own
custom unlabelled magnets from steel bar stock.

Best wishes,

Larry

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Cartwright                    Retired Physics Teacher
<exit60@cablespeed.com>              Charlotte MI 48813 USA
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- Good judgment comes from experience,
  and a lot of that comes from bad judgment.
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                        -- The Cowboys' Guide To Life
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