A rigid rod of mass m3 is povited at point A, and masses m1 and m2 are hanging from it, as shown. Point A L1 m3 L2 m1 m2 (a) What is the normal force acting on the pivot point? (b) What is the ratio of L1 to L2, where these are the distances from the pivot point to m1 and m2, respectively? Assume m2 = 2m1 and m3 = 3m1.