Air in a piston-cylinder assembly expands slowly from an initial state where the pressure is 250 kPa and the volume is 0.02 m3 to a final state where the volume is 0.1 m3 and the temperature is 500 K. The pressure of the gas varies linearly with volume during the process and ideal gas behavior can be assumed for air. Determine the heat transfer if the mass of air is 0.07259 kg.