Problem 3 A baffled stirred tank is used to mix the components of bone cement prior to packaging. The mixing time is critical in order to maintain the crystalline structure and distribution of particles within the material. Recall the powder is mixed with a sterile liquid in the surgical suite. The pilot size tank is 18-cm in diameter stirred with a 6.0-cm turbine impeller. Satisfactory results were obtained with a stir speed of 42 rpm. The production tank will be 45-cm in diameter. The average density of the dry bone cement material is 985 kg/m with an apparent viscosity of 5.0 cP over the expect range of shear rates in this dry state. a) What is the stir speed needed to scale-up by mixing time? b) What is the ratio of the power input per volume between the two scales (P2/12) when L(P1/V2). scaled by constant mixing time