Scale-up of an agitated tank, experiments with a small-scale agitated tank are to be used to design a geometrically similar installation with linear dimensions 10 times as large. The fluid in the large tank will be a heavy oil with μ = 13.5 cp and p = 0.9 g/cm³. The large tank is to have an impeller speed of 120 rpm. 

(a) Determine the impeller speed for the small-scale model, in accordance with the criteria for scale-up given in Example 3.7-2. 

(b) Determine the operating temperature for the model if water is to be used as the stirred fluid.