Refrigerant 134a Entersanozzleat200lbf/in,220F, withavelocityof120ft/sandexitsat20l bf/in with 2 velocity of 1500 ft/s. The inlet area of the nozzle is 10 in , and heat is being lost at 15 Btu/lbm. For steady-state operation, determine (a) the exit temperature (in oF) (b) the quality of R-134a at the exit. (c) the mass flow rate of the R-134a (in lbm/s) (d) the exit area of the nozzle (in in2).

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?

Aheavily insulated piston-cylinder device contains 0.02 m3 of steam at 300 kpa and 200 °c. 1.2 mpa. d this process. team is now compressed in a reversible manner to a pressure of etermine the entropy change and the work done on the steam during this process

Apressure vessel with an r/t 20 cannot be treated as thin walled vessel. a)-trune b)- false