How Does a Rocket works火箭是如何運作的？

游余

Have you noticed what happens if you let theair out of a balloon？ The air goes one way and theballoon moves in the other way. Rockets work inmuch the same way. Waste1 air comes out of therocket at high speed2 and pushes the rocket forward.

Most modern launchers3， such as EuropesAriane 5， are made up of a great number of parts.They are very heavy. Most things in the rockets arefuel4. Rockets need so much fuel to get over Earthsgravity5. Only when they reach a speed of 28，000km/h are they traveling fast enough to get into orbit6.

Most rockets are made up of two or three stages7.When a stage has used up all of its fuel， it breaksaway. It then falls back （usually into the ocean and farfrom people） or burns up in the air.

Large launchers often get another boost8 fromrockets of the first stage. These may use solid9 orliquid10 fuel. They， too， are usually thrown awayafter use.

你有沒有注意到，如果把氣球里的空氣放出來會發(fā)生什么呢？空氣朝一個方向流出，而氣球會朝另一個方向移動?；鸺倪\作原理大致相同。廢氣從火箭中高速排出，推動火箭前進。

大多數(shù)現(xiàn)代發(fā)射器，如歐洲的阿麗亞娜五號，由很多部分組成。它們很重。火箭里大部分都是燃料?；鸺枰绱硕嗟娜剂喜拍芸朔厍虻囊ΑＶ挥挟?dāng)它們達到每小時28000 公里的速度時，才能以足夠快的速度進入軌道。

大多數(shù)火箭由兩級或三級組成。當(dāng)火箭的一級耗盡了所有燃料后，它就會分離，然后會落回地球（通常會落到海洋中，遠離人群）或在大氣中燃燒掉。

大型發(fā)射器通常會從第一級火箭中獲得更多的動力。這些火箭使用的是固體或液體燃料，燃盡之后也會被丟掉。

Notes

1. waste 材料；物質(zhì)等；廢棄的；無用的

2. speed 運動；速度

3. launcher 火箭；導(dǎo)彈等的；發(fā)射器；運載火箭

4. fuel 燃料；燃燒劑

5. gravity 重力；地心引力

6. orbit 環(huán)繞地球；太陽等運行的；軌道

7. stage 火箭的；級

8. boost 推動；促進；推動力

9. solid 固體的；固態(tài)的

10. liquid [ ] . 液態(tài)的袁液化的