The two-tank mixing process shown in Fig. P514 contains a recirculation loop that transfers solution from tank 2 to tanki at a flow rate of ago go 9=1 cm x) = feed concentration Fi FIGURE P5-14 (a) Develop a transfer function that relates the concentration c2 in tank 2 to the concentration x in the feed, that is, C2 (s\/X(s) where C2 and X are deviation variables. For convenience, assume that the initial concentrations are x = c1 = C2 = 0. (b) If a unit-step change in x occurs, determine the time needed for c2 to reach 60 percent of its ultimate value for the cases where a = 0,1, and (c) Sketch the response for a = . Assume that each tank has a constant holdup volume of 1 ft3. Neglect transportation lag in the line connecting the tanks and the recirculation line. Try to answer parts (b) and (c) by intuition