Electrostatics - probably a standard question

[exuberant.me]

Q) A solid non-conducting sphere of radius R carries non-uniform charge distribution with charge density ρ = ρ_s(r/R), where ρ_s is a constant. Show that
(a) the total charge on the sphere is Q = ∏ρ_sR³, and
(b) find the electric field inside the sphere.

Now first part (a) is fairly easy,
assumed a sphere of radius x and then after further integration got the result

But i need an idea for the second part..
since there is no symmetry so "Gauss" theorem is of no use applying...
I think i need an integration there as well. But can someone provide me an idea on how to continue further. Thanks in advance.

 

[mfb]

since there is no symmetry so "Gauss" theorem is of no use applying...

There is a spherical symmetry.

 

[barryj]

How did you get the answer to part a. It seems incorrect to me.

 

[barryj]

Never mind, I got it.

 

[exuberant.me]

Never mind, I got it.

what about the electric field?

 

[Dick]

what about the electric field?

Use Gauss' theorem. Find the charge enclosed in a radius r'<R. Use integration.