Question about polarization density

[Guy ML]

Homework Statement

Given a sphere with radius R, centered at (0,0,0), it's dipole density given as $P\left(\vec{r}\right)=\alpha\left(R-r\right)\hat{z}$ where r is the distance from the center of the ball.

I'm required to find:

1. Bound charge density inside the sphere, bound charge density on the surface of the sphere.
2. Electric potential in the entire space.
3. Electric field inside the sphere and when r=R.

Homework Equations

The Attempt at a Solution

I do not know where and how to start, I thought about converting to spherical coordinates because there is no dependency on $\theta$ or $\phi$ but I don't know how that'll help me.Thanks!

 

[Paul Colby]

In your course work, what equation connects charge density with the electric field. Have they talked about $E$ and $D$ fields?