Question

The cylinder-piston device holds 0.2 m of air at a pressure of 200 kPa, at which condition a linear spring touches the piston.  But without force acting on the piston as shown in the following figure, the air is heated until the volume and pressure change to 0.5 m and 800 kPa, respectively. Find (a) the total work performed by the air; (b) the work performed against the spring.  (c) Draw a Pu diagram showing the process. (Answer (a) 150 KJ (b) 90 kJ).