Air enters a horizontal, constant-diameter heating duct operating at steady state at 290 K, 1 bar, and volumetric flow rate of 0.25 m^3/s. The flow area is 0.04 m^2. The air exits at 325 K and 0.95 bar. Assuming the ideal gas model with k = 1.4, determine: a. The mass flow rate, in kg/s.
b. The velocity at the inlet and exit, each in m/s.
c. The rate of heat transfer, in kW.