来自《耶鲁大学开放课程：基础物理 第1集 第1集》

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  So the product of Newtonian mechanics
  所以牛顿力学
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  of predicting the future given the present,
  基于现状对未来的预测
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  has got two parts,
  包含两个部分
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  and one is called kinematics
  一部分被称为运动学
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  and the other is called dynamics.
  而另一部分被称为动力学
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  So, kinematics is a complete description of the present.
  运动学是对现在的完整描述
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  It's a list of what you have to know about a system right now.
  它包含系统当前的全部必要信息
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  For example,
  比如说
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  if you're talking about the chalk--if I throw the chalk,
  这支粉笔 如果我扔出这支粉笔
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  you will have to know where it is and how fast it's moving.
  你就想知道它的位置和速度
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  Dynamics then tells you why the object goes up,
  而动力学则会告诉你为什么物体向上运动
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  why the object goes down and why is it pulled down and so on.
  为什么向下运动 为什么停下来 等等