Air is contained in a vertical piston–cylinder assembly such that the piston is in static equilibrium. the atmosphere exerts a pressure of 101 kpa on top of the 0.5-m-diameter piston. the gage pressure of the air inside the cylinder is 1.2 kpa. the local acceleration of gravity is g = 9.81 m/s2 . subsequently, a weight is placed on top of the piston causing the piston to fall until reaching a new static equilibrium position. at this position, the gage pressure of the air inside the cylinder is 2.8 kpa. determine (a) the mass of the piston, in kg, and (b) the mass of the added weight, in kg