AP Thermo and problem 63

We have emphasized the pure processes in our thermo work, but it is certainly possible for a process to be none of these. Heat in or out with a change in volume and pressure and temperature is the norm. The delta Us can be found from the end point temperatures, using c and n, but the work is best found from the area under the P vs V curve. In problem 63 process C-A, this area is RECTANGLE 20,000 X (40-80) plus a TRIANGLE (200,000 -20,000) high with a base of (40-80) m3. Given the work and the change i n U , you can figure out Q.