Spherical distribution of negative charge with two protons

[nixx986]

Imagine a sphere of radius a filled with negative charge of uniform denisty, the total charge being equivalen to that of two electrons. Imbed in this jelly of negative charge two protons and assume that in spite of their presence the negative charge distribution remains uniform. Where must the protons be located so that the force on each of them is zero?

 

[stunner5000pt]

well ok imagine there's a concetric sphere inside the main sphere where the protons are on the surface of this new sphere. In this new sphere what is the eenclosed charge??
remember dq = o dV where o is sigma
from here u can find the elctric field due to the negative charge of the sphere inside. From the electric field u can calculate the force of the negative sphere upon each proton. Also find hte force between the protons. the force of the negative sphere on each of the protons must be the same as the repulsive force of the protons on each other.