A spherical balloon is filled with helium at sea level. Helium and balloon material together weight 500 N. If the net upward lift force on the balloon is also 500 N, what is the diameter of the balloon?
- A. 5.42m
- B. 6.78m
- C. 3.43m
- D. 2.34m
Answer: A. 5.42m
Explanation: Buoyant force = Weight + Lift = 500 + 500 = 1000 N. 1000 = rho_air * g * V. V = 83.2 m³. D = 5.42 m.