What is the distance, in kilometers, of a point outside the sphere from the sphere’s center, if the potential at the point is 5.2 MV?

Question

The surface of a sphere carries a uniform charge 1.45 C. I keep getting 2.509 * 10^3 for r which is wrong. Please show your work and thanks in advance!

Answer 1

V = kQ/R where k = 8.99 x 10⁹, R is the distance in meters.

R = kQ / V = 8.99 x 10⁹ x 1.45 / 5.2 x 10⁶

R = 2.5 x 10³ meters or 2.5 km.

This is essentially what you got but your result is in meters.