A loaded porter governor has 4 link each 25 cm long, 2 revolving masses each weighing, to N and a central dead weight weighing 200 N. All the links are attached to respective sleeves at radial distances of 4 cm from the axis of rotation. The masses revolve at a radius of 15 cm at minimum speed and at a radius of 20 cm at maximum speed. Determine the range of speed.