3) A non-rotating shaft made of AISI 1018 CD steel is machined to the shape shown below. A load Fy=-250 lbr (pointing down) and Fx = F = 0 lbr is repeatedly applied and removed. Determine the minimum factor of safety for fatigue at point A, based on infinite life. If the life is not infinite, estimate the number of cycles to failure. a) Estimate the number of cycles to failure b) If the bar is also placed in an environment with a temperature of 750 F, estimate the number of cycles to failure 2 in 9 in 1-in dia -in R. 1-in dia. -in dia. 12 in B 2 in 1-in dia.