Solving the Electric Field of a Spherical Shell

[DrMcDreamy]

Homework Statement

This is a two part problem:

3- A conducting spherical shell of radius 19 cm carries a net charge of −8.15 μC uniformly distributed on its surface. Find the electric field at points just outside the shell. (Take the radially outward direction to be positive.) Answer in units of N/C.

Homework Equations

E = k\frac{F}{q}

The Attempt at a Solution

E=k\frac{8.15x10^-6 C}{(.19 m)^2}=
E= 2.03x10^6\frac{Nm}{C}

4- Find the electric field at points inside the shell. Answer in units of N/C.

I am not sure how to do this part.

 

[DrMcDreamy]

The answer I had gotten (2.03e6) is wrong. Why?

 

[Berko]

The charge is negative.