4.3 a heat engine, operating on a carnot cycle and having thermal efficiency of 80%, receives heat from a heat source at 1200°c. the power output of the engine is 500 kw. determine: a) the rate at which heat is supplied to the engine in kj/h. b) the rate at which heat is rejected to the sink in kj/h. c) the temperature of the heat sink in °c. 4.4 he a ting on innvironmental che dicen the u ssrw determ unit and the mate w 4.5 for -45 fon