The following description applies to the next threeproblems.
Air enters steadily an electrical hair dryer at 100 kPa and 27C. It leaves the hairdryer at a temperature of 80 C, an exitvelocity of 10 m/s, and at the same pressure. The exit and inletareas are 20 cm2 and 40 cm2 respectively.
(Assume properties of air cp= 1.007 kJ/kg.K, cv = 0.72 kJ/kg.K,and R= 0. 287 kJ/kg.K )
The mass flow rate of air entering the hairdryer, in kg/s, iscloser to
The velocity of the air at the inlet of the hairdryer, in m/s,is closer to
The total power the hairdryer needs to operate at the statedconditions, in kW, is closer to:
