P6.029 (GO Tutorial) The impeller shaft of a fluid agitator transmits 20 kW at 370 rpm. If the allowable shear stress in the impeller shaft must be limited to 70 MPa, determine (a) the minimum diameter required for a solid impeller shaft. (b) the maximum inside diameter permitted for a hollow impeller shaft if the outside diameter is 38 mm. (c) the percent savings in weight realized if the hollow shaft is used instead of the solid shaft. (Hint: The weight of a shaft is proportional to its cross-sectional area.) Answers: (a) Dmin = mm (b) dmax = mm (c) Percent Weight Savings = %