How a hot air balloon works
The picture below shows how a hot balloon works. Summarise the information by selecting and reporting the main features. Write at least 150 words.
1. Analyse
For this type of Diagram/Object question, it is important that you understand the relationship between the components of that Object. In addition, how to structure your writing to best depict this relationship.
Usually, this type of writing will be divided into 2 parts:
Part 1: talk about the structure of object
Part 2: talk about how that object works.
In this topic, we will break it down as follows:
Paragraph 1: The structure of the Balloon, talk about information related to envelope and information related to basket
Paragraph 2: How the balloon works, talk about how to make the balloon fly and how to control the balloon.
2. Writing sample:
The diagram depicts the construction of a hot air balloon and its working mechanism.
Overall, the construction consists of several parts, including the envelope, the skirt, the burner and the basket. It is also clear from the diagrams that the mechanism of a typical hot-air balloon involves the upward circulation of hot air.
As can be seen from the picture, the balloon, also called the envelope, is the largest part and this is a combination of multiple strips of fabric called gores. These gores are made by many nylon panels sewed together. The gores altogether form the balloon shape when fully inflated. On top of the envelop is a parachute valve, whose function is to open or close like a sealing flap. This allows hot air to escape in a controlled manner. The skirt is at the base of the envelope and the inside is made from a flame-resistant material to withstand the heat from the burners. The burners are fixed to a metal frame below the skirt and above the basket, which provides seats for passengers and the propane cylinders. These burners function as an engine, mixing propane with oxygen to generate hot air for the balloon.
As for the working mechanism, hot air is fed into the envelope by the burners. The hot air inside is lighter than the cold air outside, thus providing a buoyant force to lift the entire structure.