A tank of 0.05 m^3 volume air at 800 kpa (absolute) and 15 c. At t=0, air begins escaping from the tank through a valve with a flow area of 65 mm^2. The air passing through the valve has a speed of 300 m/s and a density of 6 kg/m^3. determine the instantaneous rate of change of density in the tank at t+0.