An ideal gas, initially at 25oc and 1 bar, undergoes the following cyclic processes in a closed system: (a) in mechanically reversible processes, it is first compressed adiabatically to 5 bar then cooled at a constant pressure of 5 bar to 25oc, and finally expanded isother. mally to its original pressure. (b) the cycle is irreversible and each step has an efficiency of 80% compared with the corresponding mechanically reversible process. the cycle still consists of an adiabatic compression step, an isobaric cooling step, and an isothermal expansion. calculate q, w, au, and ah for each step of the process and for the cycle. take cp (7/2) r and cv (5/2) r.