# E of Infinite Thin Plane

1. Sep 27, 2010

### maherelharake

1. The problem statement, all variables and given/known data
An infinite plane (2y+z=3) has surface charge density of sigma=2 microC/m2. Find the electric field at (0,0,2)m

2. Relevant equations

3. The attempt at a solution
Would this just be E=sigma/2*epsilon-naught? Would the answer just be 1 microC/m2 over epsilon-naught?

2. Sep 27, 2010

### Mindscrape

So that would be the right magnitude, but what about direction?

3. Sep 28, 2010

### maherelharake

Isn't it just the direction normal to the plane? In this case would it be (0,2,1)?

4. Sep 28, 2010

### Mindscrape

Right, and really you want a unit vector so divide by sqrt(5). Looks good to me.

5. Sep 28, 2010

### maherelharake

I think both components are supposed to be negative, but either way I got it it now. Thanks.

6. Sep 28, 2010

### Mindscrape

Oh right, well I suppose that, yeah, you will have the negative. I spaced that one out.

7. Sep 28, 2010

### maherelharake

No problem. Thanks.