Ashaft 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. (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? do the calculation. did it turn out as you expected?