The hydrofoil boat has an A-36 steel propeller shaft that is 100 ft long. It is connected to an in-line diesel engine that delivers a maximum power of 2490 hp and causes the shaft to

The question is incomplete. The complete question is :

The hydrofoil boat has an A-36 steel propeller shaft that is 100 ft long. It is connected to an in-line diesel engine that delivers a maximum power of 2590 hp and causes the shaft to rotate at 1700 rpm . If the outer diameter of the shaft is 8 in. and the wall thickness is  in.

A) Determine the maximum shear stress developed in the shaft.

= ?

B) Also, what is the "wind up," or angle of twist in the shaft at full power?

= ?

Solution :

Given :

Angular speed, ω = 1700 rpm

Power

          = 1424500 ft. lb/s

Torque,

                 = 8001.27 lb.ft

A). Therefore, maximum shear stress is given by :

Applying the torsion formula

      = 2.93 ksi

B). Angle of twist :

         = 0.08002 rad

         = 4.58°

can you make it more obvious. i can't see it properly