The sleeve arm and the ball arm of a Hartnell governor are 9 cm and 10 cm long respectively. At mean position of the sleeve, the equilibrium speed is 300 rpm and balls rotates at the radius of 12cm. The mass of each ball is 2 kg and the sleeve movement is ± 2 cm from the mean position. The minimum speed is 96% of the mean speed. Determine the stiffness of the spring and the maximum speed of the governor.