Amass of 3 kg of water is contained in a freely moving piston- cylinder device such that the pressure remains 400 kpa. initially, 1.17kg is in the liquid phase and the rest is vapor. heat is added to the system until the temperature reaches 400°c. determine: a)- the initial temperature, in 0c b)- the initial volume in m^3 c)- the final volume, in m3. d)- the boundary work done, in k). е)- the amount of heat transfer, ink).

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]