来自《耶鲁大学开放课程：基础物理 第4集 第4集》

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  on how to put this law to work,
  来说明如何应用该定律
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  because I think I at least made you realize
  因为我觉得至少得让你们意识到
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  that simply writing down the law
  只是简单地写下该定律
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  does not give you a good feeling for how you actually use it.
  是无法很好地体会如何实际应用它的
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  So, maybe you have understood it,
  可能你们已经懂这条定律了
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  but I'm going to remind you one more time
  但我要再次提醒你们
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  on how you're supposed to use this law.
  这条定律应该如何应用
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  So, I'm going to take a concrete example.
  我要讲一个具体的例子
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  The use of any law of physics
  物理学定律的用途
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  is to be able to predict something about the future,
  就是在给定当前的状态的情况下
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  given something about the present.
  去预测未来的一些事情
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  So, all problems that we solve can be categorized that way.
  我们解决的所有问题都能这样分类