A shaft made of AISI 1020 cold-drawn steel rotates at 1600 rpm and transmits 8 HP. (a) Using the maximum shear stress theory, determine the minimum acceptable diameter of the shaft so that there is a factor of safety of 1:8. 1 (b) Suppose the shaft still transmits 8 HP, but now the shaft rotates at twice the original speed, i. e., at 3200 rpm. Before doing a calculation, can you speculate about whether the required minimum diameter would increase, decrease or stay the same