Go Back   Physics Help Forum > College/University Physics Help > Advanced Electricity and Magnetism

Advanced Electricity and Magnetism Advanced Electricity and Magnetism Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old May 13th 2011, 10:38 AM   #1
Member
 
Join Date: Nov 2010
Posts: 40
Questions about retarded field E and B

I have a few question from the book. I am going to split into multiple posts due to the limitation of the number of images per post. These are the formulas from the book which I understand:

(10.65)

(10.66)

Where




Last edited by yungman; May 13th 2011 at 10:51 AM.
yungman is offline   Reply With Quote
Old May 13th 2011, 10:48 AM   #2
Member
 
Join Date: Nov 2010
Posts: 40
Below I copy straight from the book and I will point out my question at the end:


[BOOK]

The quantity in brackets of (10.66) is strikingly similar to the one in (10.65), which can be written, using BAC-CAB rule as ; the main difference is that we have v instead of u in the first two terms.

1) In fact since it's all crossed into anyway, we can with impunity change these v into -u; the extra term proportional to disappears in the crass product.

2) The first term in E in (10.65) ( the one involve (c^2-v^2)u) falls off as the inverse square of the distance from the particle.

1) The second term( the one involving is therefore dominant at large distance.


[END BOOK]

Last edited by topsquark; May 13th 2011 at 01:38 PM. Reason: Removed the color from line 2.
yungman is offline   Reply With Quote
Old May 13th 2011, 10:49 AM   #3
Member
 
Join Date: Nov 2010
Posts: 40
These are my questions, the numbers correspond to the number of the last post:

1) I have no ideas what the book said.




2) Is this imply using the first part of the equation of (10.65) shown below that it is proportion to ?






3) Does this imply E proportion to as shown below?



Thanks

Alan
yungman is offline   Reply With Quote
Old May 13th 2011, 01:50 PM   #4
Forum Admin
 
topsquark's Avatar
 
Join Date: Apr 2008
Location: On the dance floor, baby!
Posts: 2,468
Originally Posted by yungman View Post
These are my questions, the numbers correspond to the number of the last post:

1) I have no ideas what the book said.


so we might as well just sub in -v for u.

Originally Posted by yungman View Post
2) Is this imply using the first part of the equation of (10.65) shown below that it is proportion to ?






3) Does this imply E proportion to 1/(eta) as shown below?


Yes.

-Dan
__________________
Do not meddle in the affairs of dragons for you are crunchy and taste good with ketchup.

See the forum rules here.
topsquark is online now   Reply With Quote
Old May 13th 2011, 03:40 PM   #5
Member
 
Join Date: Nov 2010
Posts: 40
Thanks, I really appreciate your help.

Last edited by yungman; May 13th 2011 at 03:42 PM.
yungman is offline   Reply With Quote
Old May 19th 2011, 07:12 AM   #6
Member
 
Join Date: Nov 2010
Posts: 40
Originally Posted by topsquark View Post


-Dan

What is the physical meaning of u?
yungman is offline   Reply With Quote
Reply

  Physics Help Forum > College/University Physics Help > Advanced Electricity and Magnetism

Tags
field, questions, retarded



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Please verify my work and help solving the intrgration on retarded potential problem. yungman Advanced Electricity and Magnetism 5 May 7th 2011 11:15 AM
Position and velocity vector for the charge in finding retarded potential. yungman Advanced Electricity and Magnetism 4 May 5th 2011 11:33 AM
Please help with this derivation on part of the retarded potential yungman Advanced Electricity and Magnetism 4 Apr 24th 2011 10:33 PM
Questions! jello17 Kinematics and Dynamics 3 Oct 12th 2008 08:16 PM
Questions jello17 Kinematics and Dynamics 3 Oct 4th 2008 09:31 PM


Facebook Twitter Google+ RSS Feed