申論題

(20%) 3. A propeller shaft for a small yacht is made of a solid steel bar 104 mm in diameter. The allowable stress in shear is 48 MPa, and the allowable rate of twist is 2.0° in 3.5 meters.

(b) Repeat part (a) if the shaft is now hollow with inner diameter of 5d/8. Compare Values to corresponding values from part (a). (10%)