From: poutnik@privacy.net   
      
   Dne 15/11/2017 v 22:50 Luigi Fortunati napsal(a):   
   > Tom Roberts mercoled=EF=BF=BD 15/11/2017 alle ore 09:16:36 ha scritto:   
   >> The reaction to the centripetal force of the above rope   
   >> pulling on the stone is simply the tension of the rope pulling on the ha=   
   nd.   
   >   
   > The tension of the rope pulling on his hand would not exist if there   
   > was not a rock FORCE on the rope to make it "tense".   
   >   
   >> But you also seem to be confused about the reality of   
   >> "centrifugal force" and the utter impossibility of it to "cause" anythin=   
   g.   
   >   
   > Centrifugal force causes (for example) the "real" effect of the Earth's   
   > crushing to the poles and its enlargement to the equator.   
   >   
   Remember the centrifugal force is used in 2 different meanings.   
      
   Mainly in common language and technology: reactive force   
      
        Centrifugal force is normal real reactive force   
        in circular scenario. It is equivalent to the scenario   
        of linearly applied force.   
      
        The rope is pulling an object by acting centripetal force.   
        The object is pulling the rope by reacting centrifugal force.   
      
        The same can be presented by the linear rope pulling.   
      
        The rope is pulling an object by acting linear force.   
        The object is pulling the rope by reacting linear force.   
      
      
   in Physics: fictitious force   
      
        Centrifugal force is one of fictitious forces,   
        not existing in inertial coordinate systems.   
      
        Fictitious forces are *formally* added terms   
        to the 2nd Newton motion law  to describe motion of objects   
        in non inertial rotating coordinate systems.   
      
        In this way they save the formal validity   
        of the 1st Newton law   
        for non inertial coordinate systems.   
      
        As in noninertial coordinate systems,   
        objects with nonzero external net force   
        DO NOT stay in rest or in a straigth steady motion.   
      
      
   --   
   Poutnik ( The Pilgrim, Der Wanderer )   
      
   A wise man guards words he says,   
   as they say about him more,   
   than he says about the subject.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)