The hot air balloon is not a suitable means of transport for people who need to get to a certain place quickly, because it moves at the same speed as the winds. But it is very suitable for those people who want to enjoy the experience of flying. But how does he manage to fly? What physical principle explains the flight of balloons?
Air, like all materials, undergoes the phenomenon of expansion and contraction when heated and cooled, respectively. When heating a given mass of gas, dilation of it and as a result it becomes less dense, so that it rises to the surface leaving the air cooler at the bottom, as this is denser. Air dilation is the physical principle that explains the flight of a balloon and it takes off in the following way: inside a balloon the air is heated by means of a flame that comes out of a gas nozzle. When heated, the air becomes lighter, that is, less dense, and in this way it rises by pressing on the walls of the balloon, making it rise.
To keep the balloon always in the air, a burner is used, which is facing the mouth of the balloon, when the air cools, the burner is fired to heat it up, so the balloon stays in the air for a good amount of time. time.
By Marco Aurélio da Silva
Source: Brazil School - https://brasilescola.uol.com.br/fisica/a-ascensao-um-balao-ao-ceu.htm