Figure 1 shows a Porter governor in its lowest position. All four arms are 300 mm long and are pivoted on the axis of the spindle (at the top and at the sleeve). Each ball has a mass of 6 kg and the central sleeve load is 36 kg. The radius of rotation of the balls is 180 mm in the lowest position and 240 mm in the highest position. Neglecting friction, determine (a) the equilibrium speed at the lowest position (in rpm), (b) the equilibrium speed at the highest position (in rpm) and (c) the lift of the sleeve between the two positions (in mm).