A. What interference fit is required in order to transmit 100 kWw at 70 RPM between a (250mm outer diameter and I S0mm inner diameter) steel shaft and a 350 mm outside diameter cast iron hub which is 200 mm long. Also state the maximum actual tangential stresses at the various surfaces. (Take Young's modulus for the steel and cast iron to be 200 and 100GPa, respectively, assume the coefficient of friction is 0.12 and that Poisson's ratio is 0.3 for both materials.) (15 mark) B: Answer the following questions : 1: A bearing is required to support a radial load of 3000 N for a shaft of 40mm nominal diameter spinning at 900 rnm The desired life is 15 000 hours snecifv an annronriate hearine instifvine the choice