A propeller shaft for a small yacht is made of a solid steel bar 104 mm in diameter. the allowable stress in shear is 48MPa, and the allowable rate of twist is 2.0 degrees in 3.5 meters.
a) assuming that the shear modulus of elasticity is G=80GPa, determine the maximum torque Tmax that can be applied to the shaft.
b) repeat part a) if the shaft is now hollow with an inner diameter of 5d/8. Compare Tmax value to corresponding values from part a).