Trista's World--- 文字交流園地

Translated by: Trista, Lai. 賴亞萱

Source Text

Why Do Hot-air Balloons Fly?

Hot-air balloons use the difference in weight between hot air inside the balloon and colder air outside to obtain lift.

Ballooning is based on the theory of displacement. A container filled with hot air, or with a gas such as hydrogen or helium, will stay airborne. This is because the weight of the air it displaces is not less than the weight of the gas or hot air.

A hot-air balloon consists of a wicker basket in which the pilot and crew stand, a gas burner and a large airtight nylon envelope with a big opening at the base. To ascend, you turn on the burner, which heats the air inside the balloon in only a few minutes. To descend, you allow the air inside the balloon to cool. This takes quite a long time, and so the burner may be turned off for a while before the balloon starts to descend. On landing you open a ripping panel to deflate the balloon quickly and prevent the wind dragging it.

Target Text

為什麼熱氣球會飛？

熱氣球的升起，是因為內部熱空氣和外部冷空氣，不同的重力差導致的。

熱氣球能漂浮在空中，是根據浮力原理，因為氣囊內充滿了比空氣更輕的熱空氣或氫氣。

熱氣球是由一個供駕駛員和工作人員站立的藤製吊籃、一個燃燒器和一個由強化尼龍製的下口敞開大型氣囊組合而成。要上升時，需打開燃燒器，氣囊裡的空氣會在幾分鐘內，開始被加熱。下降時，你需讓氣囊內部的空氣冷卻，這需要花費比較長的時間，所以在熱氣球開始下降前，必須關掉燃燒器一段時間。降落後，打開排氣閥，馬上抽出氣囊內的空氣，避免被風再次吹移。