Go Back   Science Forums Biology Forum Molecular Biology Forum Physics Chemistry Forum > General Science Forums > Physics Forum
Register Search Today's Posts Mark Forums Read

Physics Forum Physics Forum. Discuss and ask physics questions, kinematics and other physics problems.


Simple proof has me stuck

Simple proof has me stuck - Physics Forum

Simple proof has me stuck - Physics Forum. Discuss and ask physics questions, kinematics and other physics problems.


Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 12-07-2004, 07:14 PM
Dave Hughes
Guest
 
Posts: n/a
Default Simple proof has me stuck



Hey,

I am currently working through my Nuclear Physics question sheet, and one
part of the course has me stuck. Its just a small part, but how do you
show that the potential energy due to electrostatic forces of a uniformly
charge sphere of total charge Q and radius R is

3Q^2
U=----
20*Pi*e*R

Where e is epsillon nought.

I looked in the textbook "Modern Physics" and it just says that a simple
proof can show this, albeit in a slightly rejigged way with a factor of 3
fifths at the start.

Any suggestions?

David
Reply With Quote
  #2  
Old 12-07-2004, 08:00 PM
tadchem
Guest
 
Posts: n/a
Default Simple proof has me stuck

[Only registered users see links. ]

Reply With Quote
  #3  
Old 12-07-2004, 08:00 PM
tadchem
Guest
 
Posts: n/a
Default Simple proof has me stuck

[Only registered users see links. ]

Reply With Quote
  #4  
Old 12-09-2004, 03:14 AM
Steven Gray
Guest
 
Posts: n/a
Default Simple proof has me stuck

Dave Hughes <david.hughes@hugheswalker.wanadoo.co.uk> wrote in
newsan.2004.12.07.19.14.43.215372@hugheswalker.w anadoo.co.uk:

one
uniformly
simple
3

Recognize that if you have a uniformly charged sphere of total charge Q,
radius r, and charge density p, and it has a potential energy X, then the
change in X from adding a thin shell of thickness dr is:

dX = 4*pi*r^2*p*(dr)*Q/(4*pi*e*r).

Then integrate from X=0 to X=R, using Q(r)=(4/3)*pi*r^3*p .

Eliminate p from the final answer by substituting Q(R).

--
Steve Gray
[Only registered users see links. ]
Reply With Quote
  #5  
Old 12-10-2004, 08:47 AM
Dave Hughes
Guest
 
Posts: n/a
Default Simple proof has me stuck

Thanks alot for all your help, its been very helpful.

David
Reply With Quote
Reply

Tags
proof , simple , stuck


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Moving Dimensions Theory Book Due Out in Fall 05--Very Rough Draft: 4th Dimensions Expanding Relative to 3 Spatial Dimensions jollyrogership@yahoo.com Physics Forum 64 03-31-2012 10:24 AM
A Scientific Proof of God George Hammond Science and Religion Forum 0 05-02-2009 02:57 AM
Simply put, MOVING DIMENSIONS THEORY is THE NEW MODEL: http://physicsmathforums.com drelliot@gmail.com Physics Forum 0 08-29-2006 06:32 AM
Moving Dimensions Theory!! Rock On!! drelliot@gmail.com Physics Forum 1 07-06-2006 05:19 PM


All times are GMT. The time now is 09:26 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2005 - 2012 Molecular Station | All Rights Reserved
Page generated in 0.16364 seconds with 16 queries