21 8 Motion and Power P8.21 In the motorized rack-and-pinion system in a milling machine, the pinion has 50 teeth and a pitch radius of 20 mm (Figure P8.21). Over a certain range of its motion, the motor turns at 800 rpm. (a) Determine the horizontal velocity of the rack. (b) If a peak torque of 14 N m is supplied by the motor, determine the pulling force that is produced in the rack and transferred to the milling machine. 800 rpm 14 N.m wwwwww