In a gas turbine unit, the gases flow through the turbine at 12 kg/s and the specific work done by the turbine is 750 kJ/kg. The enthalpies of gases at the inlet and outlet are 1280 kJ/kg and 450 kJ/kg respectively, and the velocity of gases at the inlet and outlet are 45 m/s and 120 m/s, respectively. Calculate: (a) The rate at which heat is rejected to the turbine. (b) The area of the inlet of the pipe given that the specific volume of the gases at the inlet is 0.4 m3/kg.