A vertical piston cylinder assembly with a piston of mass 25 kg and having a face area of 0.005 m^2 contains air. The mass of air is 2.5 g, and initially the air occupies of a volume of 2.5 liters. The atmosphere exerts a pressure of 100 kPa on the top of the piston. The volume of the air slowly decreases to 0.001 m^3 as energy with a magnitude of 1 kJ is slowly removed by heat transfer. Neglecting friction between the piston and the cylinder wall, determine the change in specific internal energy of the air, in kJ/kg. Let g=9.8 m/s^2