A balloon rises because it is filled with a gas that is lighter than air. Humans have always dreamed of flying through the air. The dream came true in 1783 when a hot-air balloon carried its first passengers.
The lightest gas is hydrogen. Hydrogen, however, catches fire and explodes easily. Coal gas produced when coal is heated without air is cheaper, but it is heavier than hydrogen and also a fire hazard. Helium, almost as light as hydrogen, does not burn. Although scarce and expensive, it is the ideal balloon gas.
A hot air balloon is controlled by the hot air from the fire witch makes it go up. If they pull a cord and it will release some hot air and put some cold air inside witch will make the balloon go down and land
The direction hot air balloon goes is in determined by the wind. At different altitudes, the wind speed and direction may be different, so a pilot has the ability to go up or down to find the wind blowing in a different direction. This is a very limited way to steer left or right.
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