Compute all parts of given question:
Question: A total electric charge of 1.50nC is distributed uniformly over the surface of a metal sphere with a radius of 26.0cm. The potential is zero at a point at infinity.
Part I: Find the value of the potential at 60.0cm from the center of the sphere.
Part II: Find the value of the potential at 26.0cm from the center of the sphere.
Part III: Find the value of the potential at 12.0cm from the center of the sphere.
I am having a hard time understanding these questions. So if you answer please explain how you found the answers.