Air enters a pipe at 50C and 200 kPa and leaves at 40C and 150 kPa. It

Question:

Air enters a pipe at 50°C and 200 kPa and leaves at 40°C and 150 kPa. It is estimated that heat is lost from the pipe in the amount of 3.3 kJ per kg of air flowing in the pipe. The diameter ratio for the pipe is D1/D2 = 1.8. Using constant specific heats for air determine the inlet and exit velocities of the air. Answers: 28.6 m/s, 120 m/s