The propeller of a wind generator is supported by a hollow circular shaft with 0.4 m outer radius and 0.3 m inner radius. The shear modulus of the material is G = 80 GPa.
(a) If the propeller exerts an 840 kN · m torque on the shaft, what is the resulting maximum shear stress?
(b) What is the angle of twist of the propeller shaft per meter of length?
