961. Twenty kilowatts are transmitted through a speed reducer. At one part of the machine, as shown in Fig. P-961, the pinion drives the gear A of shaft AB at 6 r/s. Determine the minimum diameter of shaft AB if max. o < 80 MN/m² and max. r < 60 MN/m². Consider only torsional and bending stresses in the shaft. 300 mm Gear 250 mm P.D. Figure P-961. Pinion