four point charges form a square with sides of length , as shown in the figure. in the questions thatfollow, use the constant in place of . ( intro1 figure ) parta what is the electric potential at the center of the square? make the usual assumption that the potential tends to zero faraway from a charge. express your answer in terms of , , and appropriate constants. = partb what is the contribution to the electric potential energy of the system, due to interactions involving thecharge ? express your answer in terms of , , and appropriate constants. = partc what is the total electric potential energy of this system ofcharges? express your answer in terms of , , and appropriate constants. =