12. [-/1 Points] DETAILS MY NOTES SERPSE10 22.A.P.032. ASK YOUR TEACHER PRACTICE ANOTHER A small sphere of charge g, = 0.856 uC hangs from the end of a spring as in Figure a. When another small sphere of charge G, = 0.654 uCis held beneath the first sphere as in Figure b, the spring stretches by d = 3.84 cm from its original length and reaches a new equilibrium position with a separation between the charges of r = 4.80 cm. What is the force constant of the spring? N/m f a Need Help? || Readit | Submit Answer 13. [-/2 Points] DETAILS MY NOTES SERPSE10 22.A.P.038. ASK YOUR TEACHER PRACTICE ANOTHER Four identical charged particles (g = +10.6 pC) are located on the corners of a rectangle as shown in the figure below. The dimensions of the rectangle are L = 62.4 cm and W = 14.3 cm. y q 7 W % q L 7 @ (a) Calculate the magnitude of the total electric force exerted on the charge at the lower left corner by the other three charges. " N (b) Calculate the direction of the total electric force exerted on the charge at the lower left corner by the other three charges. | @ (counterclockwise from the +x-axis) i J