2. A Porter governor has two balls each of mass 3 kg and a central load of mass 15 kg. The arms are all 200 mm long, pivoted on the axis. If the maximum and minimum radii of rotation of the balls are 160 mm and 120 mm respectively, find the range of speed. [Ans. 28.3 rpm] 3. In a Porter governor, the mass of the central load is 18 kg and the mass of each ball is 2 kg.