How to make a hot air balloon

Make a pocket similar to a hot air balloon with fine cloth or soft paper. You can't leak except your mouth. Tie several edges of the pocket with string, and tie a small basket similar to the bottom of a hot air balloon at the other end of the rope.

Pay attention to even balance, the rope length should be the same, put a small candle on the basket to prop up the pocket to avoid being burned, and then you can light the candle. When the hot air fills the pocket, you can let go and wait for the promotion.

Choose a light material. Pay attention to the comparison must be appropriate to avoid wind blowing. Try a few more times and you will succeed! I learned this in primary school! The principle is that the basic principle of hot air balloon is that it expands when heated and contracts when cooled. When air expands when heated, its specific gravity will become lighter and rise.

A hot air balloon is mainly composed of a huge airbag, a hanging basket for carrying people or articles and a burner for heating air. The burner injects the air heated by combustion into the airbag from the port at the lower part of the airbag, and the hot air gathers in the airbag to generate lift force, so that the balloon lifts the hanging basket and lifts off together.