1.A refrigerator compressor compresses 0.5 kg/s of saturated R-134A vapor at -10C to 1000 kPa and 50C. The compresser has a point that is not insulated and losess heat to the surroundings, the temperature of this point is 30C. What is the minimm work consumed by the compressor?

2.air enters an adiabatic nozzle at 4MPa and 400 K with a velocit of 25 m/s. Air at the exit is 2 MPa and a velocity of 160 m/s. Calculate entropy? Is this a reversable process?

3.Use the Muskingum method to route a flood through a reach a river. The base flow is 100 cfs, and the incoming flood flow increases 50 cfs every 2 hr over a 6 hr period and the subsides at the same rate. From past observations the time lag between peaks at the inlet and outlet of the reach is 2.5 hr, and the x coefficient is 0.35. What is the peak discharge at the reach outlet, and when does it occur?