Ammonia in a piston-cylinder assembly undergoes two processes in series. initially, the the ammonia is saturated vapor at p1 = 100 lbf/in.2 . process 1 − 2 involves cooling at constant pressure until x2 = 75%. the second process, from state 2 to state 3, involves heating at a constant volume until x3 = 100%. kinetic and potential energy effects are negligible. for 1.2 lb of ammonia: a. determine the heat transfer and work for process 1-2, in btu. b. determine the heat transfer for process 2-3, in btu.

A248-g piece of copper is dropped into 390 ml of water at 22.6 °c. the final temperature of the water was measured as 39.9 °c. calculate the initial temperature of the piece of copper. assume that all heat transfer occurs between the copper and the water. remember, the density of water is 1.0 g/m

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.

A( developed during the process of technology design