Which way does electric field line go?

AI Thread Summary
The discussion revolves around determining the net electric field at the origin due to symmetrically placed rectangular insulators with uniform charge distributions. The correct answer for the direction of the electric field at the origin is aligned with the negative x-axis. The user initially expressed confusion about how to approach the problem but later realized that identifying the direction of the electric field lines was key. They confirmed their understanding by concluding that the field lines point towards the negatively charged rectangle. The conversation highlights the importance of recognizing electric field direction in solving such problems.
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Homework Statement


Given symmetrically placed rectangular insulators with uniformly charged distributions of equal magnitude as shown in the figures be low, find the net electric field at the origin.
[PLAIN]http://img254.imageshack.us/img254/8684/electricf.jpg
In the figure above, at the origin, the net field Enet is
1. aligned with the positive y-axis.
[STRIKE]2. non-zero and is not aligned with either the x- or y-axis.[/STRIKE]
[STRIKE]3. zero and the direction is undefined.[/STRIKE]
4. aligned with the positive x-axis.
5. aligned with the negative x-axis.
6. aligned with the negative y-axis.

2 and 3 were wrong.

Homework Equations


None?


The Attempt at a Solution


I think they are asking for the direction of the electric field. Actually, I have no idea what I am supposed to solve for. I know I have to find Enet but how? Thanks in advance!
 
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I'm sorry for the double post. The answer to the above is 5 (aligned with the negative x-axis). I was on the right track, since the field lines travel towards the negatively charged rectangle. But I'm still not sure for the other 4 I'm supposed to solve for. Do I just figure out the direction of field lines? Thank you.

EDIT: Yes, I was right. Just find the direction of the field lines at (0,0). It seems I have answered my own question :)
 
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