Q1 A round rotating shaft with a groove is shown below. The shaft material is AISI 1040 CD; its ultimate tensile strength and yield strength are given in Table A-20 of the textbook. Estimate, for D = 20 mm, d = 15 mm, r = 2.5 mm, f = 0.9, the alternative torque required to fail the shaft at the notch location in 20,000 cycles. T D T