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Name: Dianne L.
Status: Student
Age: 12
Location: N/A
Country: N/A
Date: June 2003

Why is a hot air balloon shaped the way it is how does the shape help it fly better?

A hot air balloon is buoyed up by a force equal to the weight of the volume of air that is displaced by the balloon. This volume, for a closed spheroid, is maximized (ignoring the gondola etc.) when the balloon is spherical. The same thing happens with a free- floating soap bubble, which is also spherical in the absence of air flow, wire frames, and other joined bubbles.

Vince Calder

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