来自《耶鲁大学开放课程：基础物理 第17集 第17集》

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  First, I put γ=0.
  首先 我使得 γ=0
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  No friction.
  即无摩擦
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  And I just re-derived the harmonic oscillator
  我重新得到了谐振子
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  because when I got the cos(ω0·t±φ).
  因为我有 cos(ω0·t±φ)
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  Then I took a problem with friction.
  接着我加入了摩擦
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  Then, I got a solution that was just exponentially falling
  我得到的结果是以指数衰减的
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  because even though it looks like α+,
  因为尽管它看上去像 α+
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  that's a negative number, that's a negative number,
  这是个负数 这是个负数
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  in the end both are falling.
  最后两者都在下降
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  It says you pull the mass and let it go,
  就是说你拉着一个质点 然后将其放开
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  it'll relax to its initial position, it'll stop.
  它会回到其初始位置并停止
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  But all of you must know that
  不过你们应该全明白