How does a hot air balloon float and sink?

By controlling the temperature of hot air in the balloon, floating and sinking can be realized. At the opening of the airbag, there is a "fire-breathing" device. When the flame is inhaled, the temperature in the airbag rises and the balloon floats. When not spraying fire, the hot air in the airbag gradually cools down and the balloon sinks.

The rise and fall of a hot air balloon is related to the temperature in the sphere. When the temperature in the sphere is high, the gravity of the balloon will decrease. When it is less than buoyancy, the balloon rises and the air temperature in the sphere drops. When the buoyancy generated by the sphere is less than its own weight and load, the balloon begins to fall.

After being heated, the air in the balloon becomes less dense and lighter than the cold air with the same volume outside the balloon, so the balloon generates buoyancy and lifts off. Instead, let the hot air balloon land, gradually turn off the burner and let the air in the balloon cool down.

Extended data:

Hot air balloon function

1, military role

Hot air balloons were originally used for communication and reconnaissance in the military. Paris was besieged in the Franco-Prussian War of 1870, and the French sent people and letters out of the encirclement with balloons. Hydrogen balloons are widely used because of their good lift-off performance and long stay time in the air.

2. Sports and tourism

After World War II, with the development of economy, the application of high technology, the research and development of chemical fiber and the popularization of propane gas, hot air balloons have developed rapidly. Hot air balloons are mainly used for air sports and sightseeing. Because of its simple operation and low requirements for landing sites, hot air balloon has really developed into a fashionable and healthy outdoor leisure sport.

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