The stirling engine, a heat engine invented by a scottish minister, has been considered for use in automobile engines because of its efficiency. in such an engine, a gas goes through a four-step cycle: (1) expansion at constant t, (2) cooling at constant v, (3) compression at constant t to its original volume, and (4) heating at constant v to its original temperature. suppose the gas starts at a pressure of 1.23 atm and the volume of the gas changes from 0.350 to 1.31 l during its expansion at constant t. calculate the pressure of the gas at the end of this step in the cycle.