A5 cm diameter upside-down piston-cylinder device contains 0.04 kg of an ideal gas at equilibrium at 100 kpa, 300 k, occupying a volume of 0.5 m3. determine (a) the gas density in kg/m3, and (b) the specific volume in m3/kg. (c) a mass is now hung from the piston so that the piston moves down and the pressure decreases. determine the mass in kg necessary to reduce the pressure inside to 50 kpa after the piston comes to a new equilibrium. assume the piston to be weightless. (data supplied: g = 9.81 m/s2; outside pressure: 100 kpa; univ gas constant = 8.314 kj/(kmol-k).[solution] [discuss]