From: fortunati.luigi@gmail.com   
      
   George Hrabovsky il 02/11/2023 14:08:07 ha scritto:   
   >> Newton also says it: "A body exerts this force only, when another force,   
   >> impressed upon it, endeavors to change its condition; and the exercise of   
   >> this force may be considered both as resistance and impulse; it is   
   >> resistance, in so far as the body, for maintaining its present state,   
   >> withstands the force impressed; it is impulse, in so far as the body, by not   
   >> easily giving way to the impressed force of another, endeavors, to change   
   >> the state of that another. Resistance is usually ascribed to bodies at rest,   
   >> and impulse to those in motion; but motion and rest, as commonly conceived,   
   >> are only relatively distinguished; nor are these bodies always truly at   
   >> rest, which commonly are taken to be so."   
   >   
   > You suggest that inertia is a force.   
      
   It is Newton who expressly says so!   
      
   In fact, he says: "A body exerts this force (inertia, vis intima)   
   *ONLY* when another force, impressed upon it, endeavors to change its   
   condition".   
      
   Therefore, inertia becomes a force only when external conditions   
   require it (not always).   
      
   This is what happens in my animation *ONLY* during the collision: what   
   does the body m2 do on that occasion? It opposes (resists) the other   
   force (that of m1) which strives to change its condition of rest.   
      
   And m1 does the same when another force (that of m2) tries to change   
   its condition of rectilinear and uniform motion.   
      
   The inertia (the vis intima) of m1 and m2 is not always a force, it   
   becomes *ONLY* when each of the two becomes an *external* force for the   
   other.   
      
    You're disputing Newton too, not just me.   
      
    Luigi Fortunati.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)