# Electrostatic potential at a point outside a sphere

1. Feb 11, 2013

A conducting spherical shell of radius 11.0 cm is charged to a potential of 5.00*10^4 V. What is the value of the electrostatic potential 5.0 cm outside the surface of the sphere?

V=(1/[4*pi*(epsilon naught)])*(Q/r) <-- outside of the shell
V=(1/[4*pi*(epsilon naught)])*(3Q/2R) <-- inside the shell

I tried to figure out Q knowing the electrostatic potential and radius of the shell by plugging those numbers into the second equation. I then took the calculated charge and plugged it into the first equation for a point outside of the shell to determine V, but my answer is wrong. I'm not sure what I need to do.

2. Feb 11, 2013

Nevermind, I found the solution.