2. You are considering a new biomaterial design for a bone fixation pin under torsional load. The design of the material prototype is a stepped shaft i.e. the diameter "steps down" at B. In an attempt to lessen the weight of the pin, section AB is hollow while section BC is solid. The two portions are firmly attached at B and the pin is rigidly attached at A. A torque T of 0.2 in-lb is applied at point B as well as a torque T of 2.0 in-lb in the opposite direction at the free end, C. Combined, these applied torques should cause a 0.0018 radian rotation of end C away from me. The length of AB is 1 inch, the length of BC is 0.35 inches, the diameter of BC is 0.2 inches, and the inner diameter of AB is 0.15 inches. If the material is A992 steel (please use your textbook), determine the outer diameter of AB. A B T