Problem 4 (25 pts) Water at 93 °C flows through a pipe with a rectangular cross-section (sides of length 200 mm and 300 mm) made of cast iron (ε = 0.25 mm) at a flow rate of 125,000 kg/hr. Find the pressure drop per meter of pipe.

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2