A hollow shaft has an external diameter of 100 mm and internal diameter of 70 mm. It transmits 750 kW of power at 1200 rev/min. Determine and draw the maximum and minimum shear stress and the angle of twist over a 2m length, given modulus of rigidity (G) is 75 GN/m2. Part 4c A solid shaft used in the control system of an aircraft is 50 mm in diameter. The maximum allowable shear stress is 84 MPa. Determine the torsional strength (torque) of the shaft. If the solid shaft has a 40 mm hole bored in it to save weight. a. determine the new torsional strength of the tubular shaft. b. analyse the shear stress distribution across the two shafts (solid and tubular) c. suggest ways of increasing the torsional strength of the tubular shaft, without increasing its mass.