A piston–cylinder assembly (see sketch) contains 0.005m³ air at 29.4 °C. The gas forces on each side of the piston, assuming there are no frictional forces at the piston-cylinder interface, balance the weight of the piston. The piston has a cross-sectional area of 20.2 in² and a mass of 160.6 kg. The local gravitational acceleration is 9.144m/s². Determine the mass of air trapped within the cylinder. The atmospheric pressure is 101.35 kPa.