4-81 Air is contained in a cylinder device fitted with a piston-cylinder. The piston initially rest on a set of stops, and a pressure of 300 kPa is required to move the piston. Initially, the air is at 100 kPa and 27 degrees Celsius and occupies a volume of 0.4 m^3. Determine the amount of heat transferred to the air, in kJ, while increasing the temperature to 1200 K. Assume air has the constant specific heats evaluated at 300 K.