Three kg of gas in a piston–cylinder assembly undergo a process during which the relationship between pressure and specific volume is py 0.5 5 constant. The process begins with p 1 5 250 kPa and V 1 5 1.5 m 3 and ends with p 2 5 100 kPa. Determine the final specific volume, in m 3 /kg. Plot the process on a graph of pressure versus specific volume.