来自《耶鲁大学开放课程：基础物理 第10集 第10集》

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  but what you're trying to do
  但你现在想做的
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  is apply a tangential force as long as you can.
  是尽可能对它施加一个切向力
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  And the force times the distance will turn into a torque.
  力与距离相乘得到力矩
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  And that'll produce angular acceleration.
  同时又产生了角加速度
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  Another way to do that
  另一种方法是
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  if you're really high-tech is to buy yourself a rocket;
  如果你非常高端给自己买了个火箭
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  it's got some flames coming here.
  火焰从这冒出
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  Then, if you just put one rocket,
  然后 如果你只放一个火箭
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  the danger--What do you think the danger is,
  危险 你们能想到危险是什么吗
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  if you just put one of these rockets?
  如果你们只是放一个火箭在上面
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  You know what the problem may be?
  你们知道会出现什么情况吗
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  It'll certainly exert a torque.
  当然会产生一个力矩