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-----Original Message-----
From: Hugh Haskell [mailto:hhaskell@MINDSPRING.COM]
Sent: Sunday, January 06, 2002 10:29 PM
To: PHYS-L@lists.nau.edu
Subject: Re: Park City Paradox ?
At 15:36 -0700 1/5/02, Ludwik Kowalski wrote:
Is this a paradox or not? I was skiing down
on the left side of another skier this morning.
We were moving in the same direction with the
same speed. And I was speculating:
1) Suppose each of us was charged negatively.
Being at rest with respect to each other we
would repel each other by Coulomb's law.
2) But electrons drifting along two parallel
wires in the same direction produce an
attractive force between the wires.
This is true, but it is relatively easily shown that this is a
relativistic effect (even at the very low drift velocities of the
electrons). The key of the analysis is that, although the net charge
on a wire carrying a steady state current is zero, the wire (less the
negative charge of the electrons that comprise the current) is
positively charged. The net attractive force between the wires is due
to the apparent increased charge density of the oppositely charged
objects in the other wire (this is the relativistic effect).
[cut]