A hollow cylindrical steel shaft is 1.5 m long and has inner and outer diameters respectively equal to 40 and 60 mm. a) What is the largest torque that can be applied to the shaft if the shearing stress is not to exceed 120 MPa? b) What torque should be applied to the end of the shaft to produce an angle of twist of 2 degrees? Modulus of rigidity of steel is 77 GPa. 1.5 m 60 mm 40 mm