Hello everyone, I'm having troulbes figuring this one out. I found an equation in the book, tried it, but it was wrong. The problem is the following: A metal sphere of radius 15 cm has a net charge of 2.0 10-8 C. (a) What is the electric field at the sphere's surface? 7992.7 N/C (b) If V = 0 at infinity, what is the electric potential at the sphere's surface? V (c) At what distance from the sphere's surface has the electric potential decreased by 700 V? I found part (a) by finding [tex]\delta[/tex] = Q/A; Then using E = [tex]\delta[/tex]/Eo; Which was correct. But for (b) I Saw [tex]Vf - Vi = -\int E.ds.[/tex] So Vf- Vi is electric potential. So i tried: V = -E*d = -(7992.7N/C)(.15) = -1198.905 V but was wrong, any ideas why?