The rotating shaft shown in Fig. P15.5 supports two masses m1 and m2, whose weights are 4 lb and 5 lb, respectively. The dimensions are a = 2 in, b =

8 in, c = 3 in, R1 = 4 in, and R2 = 3 in. Find the magnitudes of the bearing reactions at A and B and their orientations if the shaft speed is 360 rev/min.