1. The problem statement, all variables and given/known data A sphere of radius a has a charge density that varies with distance from its center d(r) = do*(r/a)**2. Express the electric field as a function of distance from the center of the sphere r, a, do, and the permitivity of free space ez for each of the falling regions: 0<r<a 2. Relevant equations [itex]\Phi[/itex]*dA= Q/[itex]\epsilon[/itex]o 3. The attempt at a solution Using Gauss's Law I have E*4 [itex]\pi[/itex] r^2 = (4/5)*[itex]\pi[/itex]*do*r^3/ [itex]\epsilon[/itex]o so E = (1/5)*do*r/[itex]\epsilon[/itex]o But this isn't the right answer...help?