A system consisting of 10 lb of air contained within a closed, rigid tank is initially at 1 atm and 600 R. Energy is transferred to the system by heat transfer from a thermal reservoir at 900 R until the temperature of hte air is 800 R. During the process, the temperature of the system boundary where the heat transfer occurs is 900 R. Using the ideal gas model, determine the amount of energy transfer by heat, in Btu, and the amount of entropy produced in Btu/R.

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.