A planetary geartrain with N_s = 48 and N_p = 30 uses the carrier and ring gear as inputs and the sun gear as output. When viewed from the right-hand side in Figure 8.36, the hollow carrier shaft is driven at 1200 rpm clockwise, and the shaft for the ring gear is driven at 1000 rpm counterclockwise.

(a) Determine the speed and rotation direction of the sun gear.

(b) Repeat the calculation for the case in which the carrier is instead driven counterclockwise at 2400 rpm.