送交者: meiyou 于 2008-12-13, 18:13:16:

回答: 现在滑冰可以在冰上单脚滑行和转弯了 由 HunHunSheng 于 2008-12-13, 15:34:18:

• even without air, it is not a parabola, it is always an ellipse. (无内容) - steven (0 bytes) 2008-12-13, 19:47:13 (283972)
  • are you sure? the earth is not a perfect sphere. (无内容) - whoami (0 bytes) 2008-12-13, 20:29:18 (283982)
    • so? as long as you are not inside the earth, - steven (36 bytes) 2008-12-13, 22:25:27 (284002)
      • what about a montain here and valley there, - whoami (46 bytes) 2008-12-13, 23:09:11 (284005)
        • too small to make a difference. The earth crust is too thin - steven (96 bytes) 2008-12-13, 23:46:22 (284008)
          • it's small, but 蚊子大腿也是肉 (无内容) - whoami (0 bytes) 2008-12-14, 00:12:10 (284010)
            • 其实就是为了抬杠的，只要说明不是抛丸线就行了。 (无内容) - steven (0 bytes) 2008-12-14, 00:52:37 (284014)
              • Exactly. 希望大家打得热闹，吧版主曲线上的谷底填平。 (无内容) - whoami (0 bytes) 2008-12-14, 01:05:33 (284017)

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