9.14 Water flows steadily into a domestic radiator at a temperature of 80 C and leaves at a temperature of 65 C. Evaluate the heat transfer from the water per kilogram of water flowing, assuming: (a) the specific heat of water at constant pressure to be constant and equal to 4-19 10 J/kg K; (b) the enthalpy of water at a given temperature to be equal to the enthalpy of saturated water at that temperature. Deglect changes in kinetic and gravitational-potential energies.