(100 points)four identical positive chargesqare located on corners of a plastic square of widtha. theorigin is located at the center of a rectangular as indicated in the diagram. the plastic square is neutral and thepolarization of the plastic can be ignored in this problem. a. how many total electrical forces are there present on all four charges, counting each nonzero force exertedby a particle on a particle as a separate force. b. what is the total net force on the system of four charges? briefly explain how you know this. c. calculate the magnitude of the force on charge in the lower-left-hand corner. d. what is the magnitude of the net electric field farr > > afrom the square?