The impeller shaft of a fluid agitator transmits 22kW at 470 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 36 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.)