in the early 1800s much interest was taken in improving the efficiency of locomotive (or steam-powered) engines. Such devices are classified as heat engines whereby heat is supplied from a reservoir held at a higher temperature (e.g. the steam boiler in the locomotive) to a heat sink held a cooler temperature (e.g. the environment) with useful work done along the way. This concept is essentially the foundation upon which reciprocating motors operate. Here are the steps in one complete cycle of a heat engine: (1) a gas is expanded isothermally and reversibly V1 to V2 with corresponding changes in pressure (P1P2); (2) the gas is then expanded adiabatically from TH (higher temp.) at V2 to TL (lower temp.) at V3. Note that pressure also changes from P2 to P3; (3) the gas is then compressed isothermally at TL from V3 to V4 with corresponding changes in pressure (P3P4); (4) the gas is compressed adiabatically back to its initial pressure, volume, and temperature. Assume the cycle is carried out reversibly on an ideal, monatomic gas. (a) Construct a qualitative plot of pressure (P) versus volume (V) for the gas. Use points to label the pressure, volume, and temperature of the gas