Ahybrid airship is an air vehicle that achieves lift by a combination of buoyancy, as well as aerodynamic forces (e. g., the way a wing produces lift) and/or vertical thrust forces (e. g., the way a helicopter produces lift). a recent design for a hybrid airship by lockheed martin describes a vehicle that provides 80% of its lift using buoyancy and 20% from aerodynamic forces. their vehicle design has a maximum operating altitude of 10,000 ft, a cruise speed of 31 m/s (~60 knots) and uses helium to produce buoyancy. the vehicle has a displacement of 36,800 m3 , and can lift a cargo of 21,300 kg, along with 19 passengers plus 3 crew members. assuming an average mass of 90.0 kg per person, estimate the “empty mass” of the vehicle (not including cargo, people or helium). if the lift coefficient of the airship is 0.05, what should be the effective area of the lifting surfaces on the airship.