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《那些古怪又让人忧心的问题》第88期:轨道速度(4)

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5 This exponentiAl increase is the centralproblem of rocketry: The fuel required to increase your speed by 1 km/smultiplies your weight by about 1.4. To get into orbit, you need to increaseyour speed to 8 km/s, which means you'll need a lot of fuel: 1.4 ×1.4 ×1.4 ×1.4 ×1.4 ×1.4 ×1.4 ×1.4 ≈15 times the originalweight of your g a rocket to slow down carries the same problem: Every1 km/s decrease in speed multiplies your starting mass by that same factor of1.4. If you want to slow all the way down to zero - and drop gently

《那些古怪又让人忧心的问题》第88期:轨道速度(4)

5.指数式增长是火箭科学中的核心问题:速度每秒提升1千米,就需要自身质量×1.4千克的燃料。进入轨道要加速到每秒8千米,这需要1.48≈15倍自身重量的燃料。用火箭减速也会面临相同的问题,速度每减少每秒1千米,就需要1.4倍自身质量的燃料。如果想要减速到零,并轻柔地再入大气层,那么还需要额外的15倍自身质量的燃料。

6 There are some good apps and online toolsto help you spot the station, along with other neat satellites.

6.网上有许多软件可以帮你找到国际空间站和其他一些卫星的位置。

7 Either kind.

7.足球或橄榄球都行。

8 This type of play is legal in Australianrules football.

8.这么玩在澳大利亚是被允许的。

9 Using song beats to help measure the passage of timeis a technique also used in CPR training, where the song “Stayin' Alive”is used.

9. 心肺复苏也会用歌曲的节拍计算时间,使用的歌曲是Stayin' Alive(活下去)。