Two air-filled balloons each have a mass of m = 3.4 g. Each balloon hangs from the same point by its own string of length L = 0.45 m. Each balloon is rubbed to give it a static charge. Both balloons are rubbed the same amount, so each balloon has the same unknown charge (q1 = q2). The hanging balloons push away until each makes and angle of ? = 17° with respect to the vertical. Part (b) Write an expression for the magnitude of the repulsive force required to keep the left balloon in this position.