Consider the flow of an incompressible newtonian fluid between two parallel plates that are 4 mm apart. if the upper plate moves to the right with u1 = 5 m/s, while the bottom one moves to the left with u2 = 1.5 m/s, what would be the net flow rate at a cross section between the two plates? take the plate width to be 5 cm and the distance between the plates to be 4 mm.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.