A point charge Q is located a the point (0,0), a second pointcharge with charge 2Q is located at the point (1,0); a third pointcharge with charge 3Q is located at the point (0,2).
a) What is the electric potential at the point (1,1)?
b) If a fourth point charge with charge 4Q is placed at thepoint (1,1) how much potential energy will it have?