An insulated tank containing 0.4 m3 of saturated water vapor at 500kPa is connected to an initially evacuated insulatedpiston-cylinder device. The mass of the piston is such that apressure of 200 kPa is required to raise the piston. Now thevalve is opened slightly, and part of the steam flows to thecylinder, pushing the piston up. This process continues untilthe pressure in the tank falls to 200 kPa. Determine thetemperature of the steam after thermal equilibrium isestablished.