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Physics Deriving Y-component of uniform electrical rod from its electric potential formulae.

Quintessential

New member
Feb 3, 2014
7
This is essentially the problem.



And this is what I did.

Realizing the following:

E = -▽V

I simply took the derivative in regards to the vertical component, in this case "a".

So:

-dV/da [the above formulae]

And I got the following:

Κλl/(a sqrt(l^2+a^2))

Does that seem about right?

**Sorry, I have no idea on how to operate the sexy mathjax characters.
 

Klaas van Aarsen

MHB Seeker
Staff member
Mar 5, 2012
8,779
This is essentially the problem.



And this is what I did.

Realizing the following:

E = -▽V

I simply took the derivative in regards to the vertical component, in this case "a".

So:

-dV/da [the above formulae]

And I got the following:

Κλl/(a sqrt(l^2+a^2))

Does that seem about right?

**Sorry, I have no idea on how to operate the sexy mathjax characters.
Welcome to MHB, Quintessential! :)

Yep. That seems about right, although your constant looks a bit weird.

Anyway, since they are asking for the y component of the electric field at point P, I would write:

$$E_y = \frac{k_\ell Q}{y \sqrt{\ell^2 + y^2}}$$

(If you click Reply With Quote, you can see what the mathjax looks like. ;))