Nonconductive wall with charge density and finding electric field

Click For Summary
SUMMARY

The discussion centers on calculating the electric field generated by a nonconducting wall with a uniform charge density of 13.62 μC/cm², specifically at a distance of 5.7 cm from the wall. The relevant equation for this scenario is derived from Gauss's law, particularly E = σ/(2ε₀), where σ is the charge density and ε₀ is the permittivity of free space. Participants noted issues with significant figures and unit conversions, emphasizing the importance of accuracy in calculations. The correct approach assumes the wall behaves like an infinite plane due to its large dimensions.

PREREQUISITES
  • Understanding of Gauss's law
  • Familiarity with electric field calculations
  • Knowledge of charge density concepts
  • Ability to perform unit conversions, particularly in electrostatics
NEXT STEPS
  • Study the application of Gauss's law in electrostatics
  • Learn about electric fields due to infinite planes of charge
  • Review significant figures and their impact on physics calculations
  • Explore the concept of permittivity of free space (ε₀) and its role in electric field equations
USEFUL FOR

Students studying electrostatics, physics educators, and anyone tackling problems involving electric fields and charge distributions.

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
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
2
Views
5K
  • · Replies 1 ·
Replies
1
Views
969
  • · Replies 3 ·
Replies
3
Views
10K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
4
Views
4K