A vertical piston cylinder device contains a gas under pressure . The Mass of the piston is 2.5 kg and its diameter is 10 cm . Initially the piston is in contact with a linear spring in its unloaded ( no deformation) configuration ( spring constant = 1.5 kN/m). Heat is then added to the gas until the piston moves up compressing the spring by 8 cm. The barometric pressure is 750 mm Hg (S.G = 13.6). Calculate the intitial and final pressure inside the cylinder.