P6-6 Bearing reactions R₁ and R₂ are exerted on the shaft shown in the figure, which rotates at 1150 rev/min and supports a 10-kip bending force. Use a 1095 HR steel. Specify a diameter d using a design factor of 1.6 for a life of 3 min. The surfaces are machined. F = 10 kip -12 in- 6 in 6 in- d/5 R. d R₁ d/10 R. 1.5 d- R₂ d 1 in Ans. d = 2 in. with fatigue = 1.47 (sufficiently close to 1.6) 4