A centrifugal clutch carrying four shoes transmits 20 kW of power at 750 rpm. The engagement of the clutch commences at 70 percent of the running speed. The inside radius of the drum is 200 mm and the radial distance of the centre of gravity of the shoe lies at 160 mm from the centre of the spider. The coefficient of friction at the contact surface is 0.25. Determine: 4.1 the mass of each shoe. 4.2 net force exerted by each shoe on the drum surface. 4.3 the force exerted by each spring 4.4 power transmitted when the shoe is worn 2 mm and is not readjusted assuming the stiffness of the spring to be 150 kN/m.