Re: Appropriate for Gen Phys? was: comprehending electric/magnetic interactions

[Brian Whatcott <betwys1@SBCGLOBAL.NET>]

At 06:09 PM 7/3/2003 -0500,  John Clement, you wrote:
> /snip/
> Incidentally some other misconceptions involve the belief that students
> have that magnets pick up metals.  Of course they are also given
> aluminum and copper to play with.  In addition students will tell you
> that magnets lose strength because the "magnetic particles" recombine or
> they drop out when magnets are dropped.

/snip/

> John M. Clement
> Houston, TX


It's understood that John is writing in shorthand, and that he expects
us to realise that magnets do indeed pick up *some* metals,
and that *some* magnets do indeed lose strength when dropped.
So his issue is the generalization of observables, and the conceptual models
brought to bear: 'recombining magnetic particles' versus 'randomizing
 magnetic domains'.   This last arouses no great missionary zeal in me:
but I am not teaching the topic.

Brian Whatcott    Altus OK