Question

Your answer is partially correct. Try again. In the figure three identical conducting spheres initially have the following charges: sphere A, 3Q; sphere B, -7Q; and sphere C, 0. Spheres A and B are fixed in place, with a center-to-center separation that is much larger spheres. Two experiments are conducted. In experiment 1, sphere C is touched to sphere A and then (separately) to sphere B, and then it is removed. In experiment 2, starting with the same initial states, the procedure is reversed: Sphere C is touched to sphere B and then (separately) to sphere A, and then it is removed. What is the ratio of the electrostatic force between A and B at the end of experiment 2 to that at the end of experiment 1? than the Number T4.714 Units No units y the tolerance is +/-2%

Answer 1

Experiment -1 After touching sphere C with A, charge on both spheres are q_A_1 = q_C_1 =+ 3Q/2 then after touching sphere c to sphere B, charge on both spheres are q_C_1 = q_B_1 = 3Q/2 -7Q/2 = -11Q/4 Force between A & B: F_1 = kq_A_1 times q_B_1 /d^2 = k times (3Q/2)(-11Q/4)/d^2 F_1 = -33/8 kQ^2 /d^2 Experimental- 2: After touching sphere C with B, both gets charge of q_C_2 = q_B_2 = -7Q/2 then, after touching sphere C to sphere A, both gets charge of q'_C_2 = q_A_2 = -7Q/2 + 3Q/2 = -Q/4 force between A & B: F_2 = kq_A_2 times q_B_2 /d^2 = k times(-Q/4)times(-7Q/2)/d^2 F_2 = 7/8 kQ^2 /d^2 ratio = F_2 /F_1 = 7/8/33/8 = 7/33 = 0.212 no units