A certain gas is used as the working substance for the following cycle: first, the gas increases its volume at constant pressure; second, the gas expands adiabatically, further increasing its volume; next, the gas is compressed at constant pressure; finally, the gas is compressed adiabatically to its initial state. (a) Draw the cycle on a PV diagram and show where heat enters or exits(indicate which) the gas. (b) Determine whether this gas (b) Find the cycle's efficiency. Replace each volume and pressure by (PA,VA), (PB,VB), and so forth for the states where the gas transitions from one process to the next (with A being the initial state).

A certain gas is used as the working substance for the following cycle: first, the gas increases its volume at constant pressure; second, the gas expands adiabatically, further increasing its volume; next, the gas is compressed at constant pressure; finally, the gas is compressed adiabatically to its initial state. (a) Draw the cycle on a PV diagram and show where heat enters or exits(indicate which) the gas. (b) Determine whether this gas (b) Find the cycle's efficiency. Replace each volume and pressure by (PA,VA), (PB,VB), and so forth for the states where the gas transitions from one process to the next (with A being the initial state).