Pressure disturbances travel in the air at a. the speed of pressure wave b. the speed of transient air velocity c. the speed depending on the speed of any valve closure d. the speed of sound which is a constant value e. the speed of sound which depends on temperature and gas composition f. a speed as a function of all the factors listed in a to d above

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.