Consider an a-36 steel (g= 11,000 ksi) shaft made of two solid parts (ab and cd) and one tubular(hollow) part (bc). the solid parts both have a diameter of 10 in. and the tubular part has an outerdiameter of 8 in. and an inner diameter of 7 in. the shaft is supported at both ends by bearings (aand d) such that it can rotate freely, and it is subjected to 40 lb-ft and 40 lb-ft torques as shown infigure. determine the angle of twist of gear b relative to gear c.