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Newtons third law

  1. Nov 13, 2009 #1
    I was wondering, if newton's third law is true why is there motion?
  2. jcsd
  3. Nov 13, 2009 #2

    Doc Al

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    Staff: Mentor

    Why do you think that Newton's 3rd law would prevent motion? Note that the equal and opposite forces mentioned in Newton's 3rd law act on different bodies, thus they don't cancel--if that's what you're thinking.
  4. Nov 14, 2009 #3
    According to the third law.if two blocks collide each other. they apply force on each other by equation F=-F.
    note:when block hits another block. it moves when it collides with Inertia.
  5. Nov 15, 2009 #4


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    Homework Helper

    Newton's third law includes reaction forces. When an object is accelerated, it reacts with an opposing force equal in magnitude to the force accelerating it.
  6. Nov 16, 2009 #5
    It says there is no motion of their centre of mass.

    But there IS motion of the the 2 individual objects. Obviously.
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