5- In the compression stroked internal combustion engine, the heat rejected to the cooling water is 45kJ/kg and the work input is 90kJ/kg. Calculate the change in internal energy of the working fluid? 6- Air in a closed vessel of a fixed volume of 0.14m3 at a pressure of 10 bar (abs) and temperature 250 °C. If the vessel is cooled so that the pressure falls to 3.5 bar, determine the final temperature and heat transferred. ( Rair- 0.287 kJ/kg.K, and cv- 0.718 kJ/kg.K).