A gas undergoes a cycle in a piston–cylinder assembly consisting of the following three processes:Process 1–2: Constant pressure, p = 1.4 bar, V1 = 0.028 m3, W12 = 15 kJProcess 2–3: Compression with pV = constant, U3 = U2Process 3–1: Constant volume, U1 - U3 = -30 kJThere are no significant changes in kinetic or potential energy.(a) Calculate the net work for the cycle, in kJ.(b) Calculate the heat transfer for process 1–2, in kJ.

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?