An irreversible heat engine operates between a source at TH=600K and a sink at TC=300K. In one cycle the engine absorbs QH=1500J from the source, produces work W=500J and rejects the remaining heat to the sink.
(i) Calculate the magnitude of heat QC rejected to the sink.
(ii) Determine the entropy change of the source, of the sink and of the working substance for the cycle.
(iii) Evaluate the total entropy change of the universe and state whether the second law is satisfied for this engine.