A small sphere of mass m = 6.50 g and charge q = 27.2 nC is attached to the end of a string and hangs vertically as in the figure. A second charge of equal mass and charge q = -58.0 nC is located below the first charge a distance d = 2.00 cm below the first charge as in the figure. 91 + 92 (a) Find the tension in the string. N (b) If the string can withstand a maximum tension of 0.180 N, what is the smallest value d can have before the string breaks? cm