# Homework Help: Half charged spherical shell

1. Jan 27, 2009

### asi123

1. The problem statement, all variables and given/known data

Hey guys.
I got this question:
"Calculate the electric field of half a spherical shell with radius R and uniform surface charge density $$\sigma$$ along its axis of symmetry above the shell."
I guess I shell use Gauss law, the thing is that the Gauss surface will not be closed above the half spherical shell so I though about calculating the electric field for a full spherical shell and then divide it by 2 to get the electric field above the upper half spherical shell.
What do you say? is that the way to go?

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jan 27, 2009

### LowlyPion

If you're talking about losing the half away from the side that is charged, I'd think not.

From the statement I take it that the points along the axis make the charges look like concentric rings spaced at a distance according to their spherical geometry away from whatever point you are at. Like looking down at a salad bowl turned face down?

3. Jan 27, 2009

### asi123

Yeah, it's like a salad bowl turned face down
I need to find a closed Gauss surface that will contain this "bowl" and I can't think of one.

I'm sorry, I didn't understand what you mean by "If you're talking about losing the half away from the side that is charged, I'd think not.".

Thanks a lot.

4. Jan 27, 2009

### LowlyPion

I was simply referring to your notion that you would take the integral of a whole sphere and then take away the mirror of the salad bowl.

5. Jan 27, 2009