Water of 500C is cooled down to 20C. The process takes place isobarically at 5MPa. Determine the thermodynamic mean temperature of the heat source. Give a formula for a diffuser that describes the temperature change between the inlet and outlet of a perfect gas as a function of the ratio of the inlet and outlet cross-sections Ae/Aa of the diffuser and the inlet velocity Ce. Assumptions: The flow is stationary, free of losses, and incompressible (p = const.). Give an example of a system whose temperature increases without heat being added. Sketch and characterize your system to perform the following analysis: What are the process variables of your system? Draw the process variables with arrows in the sketch. What are the state variables of your system? Give the first and second law for your system. What are the state variables that change inside your system? Are there changes outside your system?