Potential due to a continuous charge distribution.

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Homework Help Overview

The discussion revolves around calculating the electric potential due to a continuous charge distribution, specifically a nonconducting rod with a uniform linear charge density. The original poster presents a problem involving the potential at a point located along the perpendicular bisector of the rod.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to calculate the potential using a specific method involving charge density and distance, but questions the validity of their approach due to discrepancies with the expected answer. Other participants suggest integrating over the length of the rod and reference methods used for infinite rods, indicating a need for proper limits in the integration.

Discussion Status

Participants are exploring different methods of integration to find the potential, with some providing alternative results. There is a recognition of the need for proper integration techniques, but no consensus has been reached on the correct method or final answer.

Contextual Notes

The original poster expresses confusion over the correctness of their method and its applicability to similar problems, while participants highlight the importance of integration in solving the problem accurately.

Ajwrighter
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1. A nonconducting rod of length L = 6cm and uniform linear charge density A = +3.68pC/M . Take V = 0 at infinity. What is V at point P at distance d = 8.0cm along the rod's perpendicular bisector?



2. V = S E * ds One half of the rod = L/2 1/4piEo = 9x10^9
R = sqrt((L/2)^2 + (D^2)) = 0.08544m




3. I've attempted this solution many times but here is the more recent.
(9x10^9) [(((3.68 x 10^-12)/0.08544 ) * (.03)*(2) ] = .0232584V



My reasoning for this method. Take the Charge density A and divide it by the Range of both sides, then multiply by the length of each side which equals .03 and then multiply it by twice to obtain V from both sides (since both sides are identical.) The problem is the answer in the back gives 24.3mV = .0243V. The method I am using, is it just a close proximity, a lucky guess? Or can my method be reproduced on similar problems to obtain a close proximity? In either case, if my method is wrong what do I need to change?
 
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You have to integrate over the length of the rod.
The calculation is the same as that in many elementary texts for an infinite rod,
but with finite limits on the integral.
 
on one of my previous methods when I integrated I get 0.02484
 
I just tried integrating another way and got 0.02358.
 

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