Nonconductive wall with charge density and finding electric field

Click For Summary

Homework Help Overview

The problem involves a nonconducting wall with a uniform charge density of 13.62 μC/cm², and the objective is to find the electric field at a distance of 5.7 cm from the wall. The context is within electrostatics, specifically relating to electric fields generated by charged surfaces.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the application of Gauss's law and the relationship between electric field and charge density. There are attempts to use the formula E=σ/2ε, but confusion arises regarding the calculations and assumptions about the wall's dimensions.

Discussion Status

Participants are actively exploring the problem, with some questioning the assumptions about the wall's size and the applicability of known formulas. There is no consensus yet, as different interpretations and calculations are being discussed.

Contextual Notes

There is uncertainty regarding the dimensions of the wall and whether it can be treated as an infinite plane. Additionally, the lack of explicit constants or definitions in the problem statement is noted as a potential source of confusion.

Dtails
Messages
9
Reaction score
0

Homework Statement


A nonconducting wall carries a uniform
charge density of 13.62 μC/cm2.
What is the electric field 5.7 cm in front of
the wall? Answer in units of N/C.



Homework Equations


Gauss's law...?


The Attempt at a Solution


Honestly, this bugger's got me scratching my head since our prof never even mentioned it in lecture, and I'm trying to get the homework done a week ahead of time. I've looked around for the relation of electric field to charge density...and it's not been pretty. I tried E=Q/e where little e is our freespace constant, but that's wrong, so I'm not seeing this right.

And I've searched everywhere on the web and not one god damned how-to for this type of problem. Anybody want to be merciful?
 
Physics news on Phys.org
Are you told the dimensions of the wall? Or are you supposed to assume that it is "very large"?

If you are 5.7 cm from a "very large wall", it essentially looks like an infinite plane doesn't it?...Surely you've calculated the field due to a uniformly charged infinite plane in your lectures?:wink:
 
You'd be amazed just how bad my prof is. We haven't. And the problem is the problem word for word. Just told it has a uniform charge density, and to find the electric field.

I did try E=σ/2ε. Shot down my answer twice with it. :/
 
Dtails said:
I did try E=σ/2ε. Shot down my answer twice with it. :/

Did you make sure to convert your answer to units of N/C? What was your answer?
 
769491 was the latest one. I take care of the coulomb and meter conversions when I punch through the calculations, so I'm not sure what exactly is up with this problem. Since the answer is rather large it might just be anal about significant figures of some sort since it doesn't define any freespace constants, as they usually do. Blah...
 
Dtails said:
769491 was the latest one.

You seem to be missing about 4 zeroes from the end of that!
 

Similar threads

Replies
2
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 1 ·
Replies
1
Views
1K
Replies
2
Views
5K
  • · Replies 3 ·
Replies
3
Views
11K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
4
Views
5K