Answer:
B = 423.64 N
Step-by-step explanation:
The thrust force in a fluid is equal to the weight of the displaced fluid,
B = ρ g V
where the density is that of air ρ=1.29 kg / m³ and the volume of the spherical balloon is
V =
v = 4/3 π 2³
V = 33.51 m³
let's calculate the thrust
B = 1.29 9.8 33.51
B = 423.64 N