Physics 2 - Electric Potential?

Question

A sphere conductor has a radius of 14cm and charge 26 * 10^-6 C. Calculate the electric field and the electric potential at:
1. r = 10cm
2. r = 20 cm
3. r = 14 cm from the center

Answer 1

I assume all 3 distances are from the center.
Within the sphere there is no electric field so v = that at the radius (ref. 1). Beyond the radius v is proportional to kQ/r, where k = 1 / (4 * pi * e0). See ref. 2 for further information on k and e0.
1. 1669117 v
2. 1168381 v
3. 1669117 v