Re: Confused by a derivation.

[Bob Sciamanda <trebor@VELOCITY.NET>]

Of course I made two boo-boos:
> E = (A/2*epsilon)*(q1 -q2 -q3 -q4) =0
should read: E = (q1-q2-q3-q4)/(A*2epsilon)  and
> E = (A/2*epsilon)*(q1 +q2 +q3 -q4) =0.
should read: E = (q1+q2+q3-q4)/(A*2epsilon)

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor
----- Original Message -----
From: "Bob Sciamanda" <trebor@VELOCITY.NET>
To: <PHYS-L@lists.nau.edu>
Sent: Monday, February 04, 2002 6:23 PM
Subject: Re: Confused by a derivation.


> From: "Michael Edmiston" <edmiston@BLUFFTON.EDU>
> > can you shed any light on how you got the q1 -q2 - q3 - q4 = 0 that I
> > asked you about?
> Convention: Since we here deal only with one-dimensional vectors, let a
> positive vector be directed to the right; a negative vector to the left.
> Then the field of an idealized planar sheet of charge is given by E =
> q/(A*2 epsilon}for points to the right of the charge layer and E
= -q/(A*2
> epsilon) for points to the left of the charge layer.  This works for
> charges(q) of either sign. This result is derivable from either a direct
> integration of Coulomb's law or from Gauss' law.
>
> In the stated configuration of layered charges q1 q2 q3 q4 (left to
> right), the net field inside the left conductor (ie a point between the
> layers q1 and q2 ) is givenb by the superposition:
> E = (A/2*epsilon)*(q1 -q2 -q3 -q4) =0
>
> In like manner the field inside the second conductor (between the layers
> q3 qnd q4) is:
> E = (A/2*epsilon)*(q1 +q2 +q3 -q4) =0.
>
> Bob Sciamanda (W3NLV)
> Physics, Edinboro Univ of PA (em)
> trebor@velocity.net
> http://www.velocity.net/~trebor