Re: [Phys-l] magnetic forces & potential energy

["Jeffrey Schnick" <JSchnick@Anselm.Edu>]

Hi Paul,

I address the force question for the case in which the separation of the
magnets is so great that you can treat them as point particles, each of
which has a magnetic dipole moment, in chapter 17 of Calculus-Based
Physics II at:
http://www.anselm.edu/internet/physics/cbphysics/downloadsII.html .
That discussion uses an equation from chapter 15.

Jeff Schnick


> -----Original Message-----
> From: phys-l-bounces@carnot.physics.buffalo.edu [mailto:phys-l-
> bounces@carnot.physics.buffalo.edu] On Behalf Of Paul Lulai
> Sent: Wednesday, May 14, 2008 11:55 AM
> To: Forum for Physics Educators
> Subject: [Phys-l] magnetic forces & potential energy
>
> Hello.
>
> I have a student that is trying to design an electric motor.  I know
> there are a million different (& easy) electric motor designs
available.
> He is trying something a bit unique.
>
> The student has magnets that state they have a 'strength' of 200
pounds.
> I believe that this is the force of attraction btn the magnet and a
> ferromagnetic substance when the two are in contact.  Is there a high
> school method (algebra or calc 1 method) that would make it possible
to
> calculate:
> 1- the force of attraction btn two magnets (one electromagnet & one
> permanent magnet) when they are separated by some distance?
> 2- the potential energy of a two magnet system in which the two
magnets
> are separated?
>
> Your help is appreciated.  I haven't used much of my e&m since I took
> the course.  It appears I've forgotten quite a bit.  A bit shameful.
>
> Thanks for your input.
>
> Paul Lulai . . . To wonder is to begin to understand
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