The early steam engines were driven by the atmosphericpressure acting on the piston fitted into a cylinder filled withsaturated

steam. A vacuum was created in the cylinder by coolingthe cylinder

externally with cold water, and thus condensing thesteam.

Consider a piston-cylinder devise with a piston surface areaof

0.1m2 initially with 0.05m3 of saturatedsteam

at the atmospheric pressure of 100kPa. Now cold water ispoured

outside the cylinder, and the steam inside starts tocondensing as a

result of heat transfer to the cooling wateroutside. If the piston

is stuck at its initial position, determinethe friction force

acting on the piston, and the amount of heattransfer when the

temperature inside the cylinder drops to30oC.