Refrigerant-134a at 600 kpa and 150°c is contained in a spring-loaded piston-cylinder device with an initial volume of 0.3m^2. the refrigerant is now cooled until its temperature is -30°c and its volume is 0.1 m3. determine the heat trans- ferred to and the work produced by the refrigerant during this process.

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk