In a Hartnell governor, the lengths of the ball and sleeve arms of a bell crank lever are 120 mm and 100 mm respectively. The fulcrum of the bell crank lever is located 140 mm from the governor axis. Each governor ball weighs 4 kg. The governor runs at 5 rps with the ball arms vertical and the sleeve arms horizontal. The sleeve movement is found to be 10 mm (upwards) for an increase in speed of 4%. Find (i) the maximum speed if the total sleeve movement is limited to 20 mm, (ii) the spring stiffness, (iii) the sensitiveness of the governor, and (iv) the required spring stiffness for isochronous operation at 300 rpm.