In a 500 MW power plant operated by the Rankine cycle, the temperature of the superheated water vapor at the turbine inlet is 873 K and the pressure is 10 MPa. The condenser outlet is saturated liquid water at 288 K. a) Calculate the thermal efficiency of the plant since the mechanical efficiencies of the turbine and the pump are 85% and 90%, respectively. b) Coal with a calorific value of 27,900 kJ/kg is used in the power plant. Since 90% of the heat released as a result of burning the coal is used, find the amount of coal (tons) required for one hour of work. c) Since the temperature rise allowed for the cooling water in the condenser is 4.5 K, find the required cooling water flow. Cr=4.184 kJ/kg K