Solve the all parts of given problem:
Problem: A total electric charge of 6.00 nC is distributed uniformly over the surface of a metal sphere with a radius of 20.0 cm. The potential is zero at a point at infinity.
Part a: Find the magnitude of the electric field at 40.0 cm from the center of the sphere.
Part b: Find the value of the potential at 40.0 cm from the center of the sphere.
Part c: Find the magnitude of the electric field at 10.0 cm from the center of the sphere.
Part d: Find the value of the potential at 15.0 cm from the center of the sphere.
I need expert help for the above problems.