Air, at an initial pressure of 0.4 MPa and temperature of 42°C, entering a duct has a velocity of 370 m/s at the inlet. At the outlet, the pressure of the air drops to 0.3 MPa and the temperature rises up to 77°C. The duct varies in cross section and the area at inlet is 5 cm2. Model air as an ideal gas and consider the duct to be insulated. Find out:

(1) the mass flow rate

(2) the velocity at output

(3) the rate of entropy production within the duct