A vertical piston cylinder arrangement with a piston mass of 60 kg with a face area of 150 cm square, contains 5 grams of air. The initial volume occupied by air is 6 liters. A decrease in internal energy amounting to 2.0 Kj occurs because of the temperature difference between the surroundings and volume inside the cylinder that caused the volume to decrease by 3 liters. The atmospheric pressure at the top of the piston is 101 KPa. Neglect the friction effects between the surface of the piston and cylinder. Determine the change in internal energy of air, in KJ/Kg.