A balloon with a mass of 90 kg is filled with helium (density = 0.179 kg/m3). The balloon is spherical and has a diameter of 11.0 m. What is the maximum mass that can be attached to the bottom of this this helium balloon, for it to be able to fly? The density of air is 1.29 kg/m^3.

Answer 1

m=90 kg
ρ(He) =0.179 kg/m³
D=11 m => R=5.5 m.
ρ(air) =1.29 kg/m³
( 4πR³/3)•g• ρ(air)= (4 πR³/3 )•g• ρ(He) + (M+m)g,
M = (4πR³/3)•{ρ(air) - ρ(He)} – m =….