Electric Potential of point outside cylinder

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SUMMARY

The discussion centers on calculating the electric potential of a point outside a charged cylinder, specifically addressing the correct definition of the separation vector in cylindrical coordinates. Participants emphasize the importance of clearly defining the geometry of the charge density, noting that the absence of symmetry complicates the problem. The correct distance formula for the separation vector is established as $$|\vec{r}-\vec{r'}|=\sqrt{(h-z)^2+s^2}$$, derived using the Pythagorean theorem. The conversation highlights the need for precise definitions and clarity in problem statements to facilitate effective problem-solving.

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jkthejetplane
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Homework Statement
So i am supposed to set up an integral with s (radial) and z to show the electric potential at a point. Part b wants you to calculate the integral in s direction and write in terms of dV/dz
Relevant Equations
V = 1/4piEps Integral (rho/r)dTau
1615001281803.png

Edit: Below is my work but i believe i have chosen the wrong values of the separation vector in the s direction. Any ideas as to what it should be?
1615000379193.png
 

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A complete statement of the problem would help us help you. What is the geometry of the charge density of the problem? Is it a thin cylinder? I guess not cause you write in your notes that there is no symmetry present. Please post a complete statement of the problem if possible.
 
Delta2 said:
A complete statement of the problem would help us help you. What is the geometry of the charge density of the problem? Is it a thin cylinder? I guess not cause you write in your notes that there is no symmetry present. Please post a complete statement of the problem if possible.
I edited it to put the whole original problem. thanks
 
##(h-z)^2+(R-s)^2##? How are you defining s?
 
haruspex said:
##(h-z)^2+(R-s)^2##? How are you defining s?
What do you mean? s is radial component in cylindrical
 
jkthejetplane said:
What do you mean? s is radial component in cylindrical
So what is the distance from (s, Φ, z) to (0, 0, h)?
 
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haruspex said:
So what is the distance from (s, Φ, z) to (0, 0, h)?
I believe that's my main question above if i am understanding you correctly. I am not sure how to define the separation vector. Right not i have it as (h-z)zhat + (r-s)shat but i am unsure on the s direction component...
 
I think the correct distance is $$|\vec{r}-\vec{r'}|=\sqrt{(h-z)^2+s^2}$$. If you do a simple figure it is straightforward pythagorean theorem.
 
jkthejetplane said:
I believe that's my main question above if i am understanding you correctly. I am not sure how to define the separation vector. Right not i have it as (h-z)zhat + (r-s)shat but i am unsure on the s direction component...
By symmetry, Φ doesn't matter, so it reduces to Cartesian: (s, z) to (0, h).
 
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