A shaft carries two steel solid discs A and B of masses 5 kg and 4.8 kg respectively, and is supported by two bearings C and D, as shown in Figure 6 below. The centre of gravity of disc A is displaced 2 mm from the axis of rotation; the centre of gravity of the disc B is displaced 1.8 mm from the axis of rotation. The displacement of B is at 90 to the displacement of the A, as shown (not to scale) on the right side of Figure 6a below. The other shown dimensions have the values a = 65 mm and L = 250 mm. For this design exercise, the weight of the shaft and the friction in the bearings can be neglected. A Lo PI a y L/2 L A Dlad P a Figure 6 2 B a) On the isometric diagram below, draw the vectors representing the horizontal, vertical and resultant forces acting on the shaft and bearings during rotation. (2 marks) y B b) Using the analytical method, calculate the dynamic forces on bearings C and D when the shaft rotates uniformly at 4000 RPM.