Gaussian shell and electric field

AI Thread Summary
The discussion focuses on calculating the electric field within Gaussian shells, specifically addressing parts of a homework problem. The calculations for parts a-c yield zero due to being within both shells, while part d results in an electric field of 7.475 N/C. The conversation also clarifies the correct use of the permittivity of free space, ε0, and provides guidance on formatting subscripts in the forum. Participants confirm the correctness of the approach and calculations, emphasizing the importance of following formatting instructions for clarity. Overall, the thread highlights both the mathematical process and the technical aspects of presenting equations in the forum.
Jrlinton
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Homework Statement


upload_2017-2-9_20-28-5.png


Homework Equations

The Attempt at a Solution


Okay, parts a-c are zero as they are within both shells.
Lets begin with d because i fear I am just repeating the same error in all of the following parts.

Part d
qenclosed=ρ(4πr^3/3-4πa^3/3)
= 1.98E-9(4π(1.5*.095m)^3/3-4π(.095m)^3/3)
=1.69E-11
E=qenc/(4πΣor^2)
=1.69E-11/(4π(8854E-12)(.1425)^2)
7.475 N/C

Now for e it should be the same process as r is equal to b and for part f the equation should be:
E=(ρ/(3Σo))*((b^3-a^3)/r^2)
 
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Jrlinton said:
Σo
I guess you mean ε0.
Jrlinton said:
1.98E-9(4π(1.5*.095m)^3/3-4π(.095m)^3/3)
=1.69E-11
Check that.

Your approach to each part looks right.
 
Yes I do mean [SUBε][/SUB0] but couldn't find the correct character nor do I understand the format for subscripts and the like.
To be clear I mean the permittivity of free space
 
Jrlinton said:
Yes I do mean [SUBε][/SUB0] but couldn't find the correct character nor do I understand the format for subscripts and the like.
To be clear I mean the permittivity of free space
If you click the Σ icon above the reply box two lines of Greek and math symbols will appear below the reply box. You can click on those to get the characters.
For subscripts, two ways:
- click on the X2 icon, then type or click on the character(s) to be subscripted. When done, move the cursor past the trailing [/ sub] control.
- after typing the text to be subscripted, select that text and click on the X2 icon.

third way.. manually type [s u b] and [/s u b] brackets, but without those embedded spaces.
 
ε0
 
that didn't seem to work.. let's try
 
I should have read your instructions more carefully...
ε0
 
Jrlinton said:
I should have read your instructions more carefully...
ε0
So should we all.:smile:
 
I appreciate it, thank you.
 
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