1. Feb 24, 2008

### jmarko10

1. The problem statement, all variables and given/known data
I have a new question if anyone could help....

The question states:
Find an expression for the electric flux passing through the surface of the Gaussian sphere as a function of r for r < a. (Use epsilon_0 for 0, rho for , Q, a, and r as necessary.)

Find an expression for the electric flux for r > a. (Use epsilon_0 for 0, p for , Q, a, and r as necessary.)

a, being the radius of the sphere and r being the given radius that is either <a, or >a

2. Feb 24, 2008

### Staff: Mentor

Present the problem exactly as given. Don't leave anything out.

3. Feb 24, 2008

### jmarko10

sorry, here is the full problem....

An insulating solid sphere of radius a has a uniform volume charge density and carries a total positive charge Q. A spherical Gaussian surface of radius r, which shares a common center with the insulating sphere, is inflated starting from r = 0.

(a) Find an expression for the electric flux passing through the surface of the Gaussian sphere as a function of r for r < a. (Use epsilon_0 for 0, rho for , Q, a, and r as necessary.)

(b) Find an expression for the electric flux for r > a. (Use epsilon_0 for 0, p for , Q, a, and r as necessary.)

4. Feb 25, 2008

### Staff: Mentor

Apply Gauss's law. What you'll need to do is find the total charge contained within the Gaussian surface as a function of r. That's just charge density times volume. (Figure out the charge density from the given information.)

5. Feb 25, 2008

### jmarko10

thanks. i did that and it worked out!