Air is heated at steady state as it flows through a constant area duct. At the inlet, the pressure is 2 bar, the temperature is 300 K and the velocity is 87 m/s. At the exit, the pressure is 1.45 bar and the velocity is 360 m/s. Neglecting potential energy effects and assuming ideal gas behavior for the air, determine the heat transfer per unit mass of air (qcv) flowing through the duct, in kJ/kg.