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Is Newton's first law a particular case of the second?

  1. Jul 28, 2011 #1
    There is not much to explain my question, really. First law says that the velocity of a body remains constant if there is no external force acting, which is just equivalent to second law, as a null force is equivalent to null acceleration, as mass cannot be null.
  2. jcsd
  3. Jul 28, 2011 #2
    Yep. I think the first law is only there to draw emphasis to this particular case.
  4. Jul 28, 2011 #3
    mathematically you can get first law from the second, but I think there is more to first law than that.First law provides definition of inertial frames and classical mechanics assumes the existence of such frames.
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