Compare this problem with Problem 57 in Chapter 23. Four identical point charges (q = + 10.0 +C) are located on the corners of a rectangle as shown in Figure P23.57. The dimensions of the rectangle are L = 60.0 cm and W = 15.0 cm. Calculate the change in electric potential energy of the system as the charge at the lower left corner in Figure P23.57 is brought to this position from infinitely far away. Assume that the other three charges in Figure P23.57 remain fixed in position.