1. The problem statement, all variables and given/known data Find the potential inside and outside uniformily charged spherical solid whose radius R and whose total charge is q.use infinity as your reference point 2. Relevant equations [tex]V=-\int E* dl[/tex] gauss law = [tex] \int E *da=q/\epsilon_ 0[/tex] 3. The attempt at a solution This should be easy. Inside a solid sphere, E=0 so the potential inside sphere is zero. The electric field of a sphere is : [tex] E_sphere=(1/(4*\pi*\epsilon_ 0))*q/R^2 [/tex] => [tex] V=-(1/(4*\pi*\epsilon_ 0))*q/R[/tex]. Hmm... my solution is too easy; I know this solution was worked out in one of the examples found in my textbooks. Should I apply gauss law I take into account that [tex] dq=\rho*d\tau=\sigma*da[/tex] where [tex] d\tau=(4/3)*\pi R^3 [/tex]and[tex] da=4*\pi*r^2[/tex] ?