Re: [Phys-l] drop a metal cylinder through a solenoid

[Carl Mungan <mungan@usna.edu>]

>   http://www.av8n.com/physics/img48/anti-capacitor.png
>
> The diagram is approximately valid in the frame instantaneously
> comoving with the bob.  In this frame there is an electric field
> (in addition to the magnetic field) ... in contrast to the lab
> frame, where there is only a magnetic field.

<snip>

> I suspect that's not entirely the explanation that was wanted,
> but perhaps it's a start.

It's a lovely and very clear explanation! (I'm puzzled by why the 
list spends more time on politics, religion, and educational policy 
than on great physics like this. But I don't mind generous use of the 
delete button, and it's a big reason I get this list in digest mode 
rather than in single-message mode.)

Perhaps my only remaining question would be: How would you frame the 
explanation in the lab frame instead? In that frame we're maintaining 
a charge separation across a finite gap d by essentially the Hall 
effect. Can I think of that like a capacitor? If so, how do I get 
away with using the vacuum permittivity?
--
Carl E Mungan, Assoc Prof of Physics  410-293-6680 (O) -3729 (F)
Naval Academy Stop 9c, 572C Holloway Rd, Annapolis MD 21402-1363
mailto:mungan@usna.edu     http://usna.edu/Users/physics/mungan/