Two spheres A and B of mass 6. 5 kg and 8. 3 kg, respectively, are separated by a distance of 0. 56 m. (a) Calculate the magnitude, in N, of the gravitational force A exerts on B and B exerts on A. Force A exerts on B N force B exerts on A N (b) If the force between the spheres is now 3. 50 10-9 N, how far apart are their centers, in meters