A solid shaft AB, of 100 mm diameter, is rigidly connected at its ends to two hollow shafts AC and ED (both of external diameter 138 mm and internal diameter 106 mm, At C and D two masses of 130 kg and 250 kg, and of radius of gyration 175 mm and 375 mm respectively, are attached to the ends of the hollow shafts. Determine from first principles the frequency of free torsional vibrations and the position of the node. Es 600mm - 400mm -1.5m -