Two liquids with different densities and viscosities fill the gap between parallel plate...

Two liquids with different densities and viscosities fill the gap between parallel plates as shown in Fig. P4.38. The bottom plate is fixed; the top plate moves with a speed of 2 ft/s. The velocity profile consists of two linear segments as indicated. The fixed control volume ABCD coincides with the system at time t = 0. Make a sketch to indicate (a) the system at time t = 0.1 s and (b) the fluid that has entered and exited the control volume in that time period.