An airship has an envelope volume of 90 000m, made up of nine separate. Sealed compartments for safety, each compartment equal in volume. The compartments ore all filled with helium under standard atmospheric conditions (101.3 kPa. 15C). A number of ballast bags are carried on, board the gondola and the airship hovers at constant altitude. Determine: a) b) c) the density and weight of the helium if Re-2077 J/kgk. the mass of the airship structure, skin and gondola. the number of 20 kg ballast bags that must be tl1rown out of the gondola to maintain altitude if one of the sealed compartments springs a leak and the helium is replaced with air. [0.1693J kg/m, 149 475 N. 531]