3. In an internal combustion engine, during the compression stroke the heat rejected to the cooling water is 50 kJ/kg and the work input is 100 kJ/kg. Calculate the change in internal energy of the working fluid stating whether it is a gain or a loss. 4. A vessel having a volume of 0.6 m³ contains 3.0 kg of liquid water and water vapor mixture in equilibrium at a pressure of 0.5 MPa. Calculate: (i) Mass and volume of the liquid. (ii) Mass and volume of the vapor. (Hint: you will need to find the quality of the vapor by using the appropriate property tables).