Infinite Sheet Potential Question

[CH1991]

Homework Statement

Please check picture below or attachment.

http://i.imgur.com/DayoP.png

Homework Equations

E=density/2 constant

The Attempt at a Solution

I know, E=density/2 constant, but how do we get potential from eletric field and how do I find it is positive or negative?

Thanks!

 

[ehild]

Recall that the electric field strength is negative gradient of the potential which is equivalent to say the potential difference V_A-V_B between points A and B is$$V_B-V_A=-\int_A^B{E_s ds}$$
Find the electric field between the plates first.

ehild

 

[CH1991]

Yeah,I did find E=density/2 constant as my eletric field, but how do I get potential?
Thanks!

 

[ehild]

Yeah,I did find E=density/2 constant as my eletric field, but how do I get potential?
Thanks!

That is the electric field from the charge distribution of one plate, but you have two plates.

You need the potential difference between the plates.
Have you read my previous post how to get the potential difference?

ehild

 

[CH1991]

You mean #2?
Thanks!

 

[CH1991]

Thank you!