A Large Spherical Air Balloon Is Filled with Helium

question 45

Multiple Choice

A large spherical air balloon is filled with helium.If the balloon is to lift three people,each approximately 80 kg,plus a basket and balloon outer covering material of mass 50 kg,calculate the minimum radius of the balloon.Assume values of the density of air and helium to be 1.29 kg/m³ and 0.18 kg/m³ respectively.

• A)62 m
• B)8.0 m
• C)4.0 m
• D)20 m
• E)5.0 m

---

Definitions:

Certified Forest

A forest area that has been assessed and recognized by a certifying body for being managed in an environmentally responsible, socially beneficial, and economically viable manner.

Forest Stewardship Council

An international non-profit organization that sets standards for responsible forest management to ensure environmental sustainability, social benefit, and economic viability.

Sustainable Forestry Initiative

A program promoting responsible forest management practices that maintain the ecological, social, and economic values of forests.

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem.