From: fortunati.luigi@gmail.com   
      
   Il 20/12/2025 08:36, Luigi Fortunati ha scritto:   
   > Luigi Fortunati wrote:   
   >> So, it's the two opposing forces on the rope that determine who wins and   
   >> who loses in a tug of war.   
   >>   
   >> It is not at all true what is said, that is, that the two opposing   
   >> forces (in tug-of-war) are always equal and opposite!   
   >>   
   >> In the end, the father wins if the force F_father_on_the_rope is greater   
   >> than the force F_son_on_the_rope. The son wins if it's the opposite, and   
   >> they tie if the two forces are equal.   
   >>   
   >> That's exactly what I was getting at.   
   >>   
   >> Can you confirm that this is indeed the case?   
   >>   
   >> Luigi Fortunati.   
   >   
   > [[Mod. note --   
   > Yes, that's correct.   
   >   
   > Newton's 3rd law tells us that the two forces   
   >    F_father_on_rope (pulling right on the rope)   
   > and   
   >    F_rope_on_father (pulling left on the father)   
   > *are* always of the same magnitude.   
   >   
   > Newton's 3rd law also tells us that the two forces   
   >    F_son_on_rope (pulling left on the rope)   
   > and   
   >    F_rope_on_son (pulling right on the son)   
   > *are* always of the same magnitude.   
   >   
   > But the two forces   
   >    F_father_on_rope (pulling right on the rope)   
   > and   
   >    F_son_on_rope (pulling left on the rope),   
   > are in general NOT of the same magnitude.  None of Newton's laws   
   > specifies which of these is larger in magnitude.   
   > -- jt]]   
      
   Very clear explanation, thank you.   
      
   If there's a rope between the father and the son, the third law applies   
   between the father and the rope, and also between the son and the rope,   
   but it doesn't apply to the father and son because they aren't in direct   
   contact.   
      
   So, let's eliminate the rope and put the father and son in direct   
   contact, as in the image https://ibb.co/rRJ5mvMC where they push each   
   other directly with their own hands.   
      
   The father says to the son: "Push toward me with your hands with all   
   your strength," and the son pushes.   
      
   The father uses only part of his force, just enough to balance the   
   son's, and thus the two opposing forces are equal, and both remain in   
   place (even though their masses are different).   
      
   Then the father wants the son to win, and reduces his force with his   
   hands, so that the son's force prevails and the father retreats a little.   
      
   Afterward, the father increases his strength to surpass that of his son   
   and advances, while the son is forced to retreat, his strength no longer   
   able to counteract that of his father.   
      
   How can all this alternating opposing forces be reconciled with the   
   third law that dictates their eternal equality?   
      
   Luigi Fortunati   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)