From: fortunati.luigi@gmail.com   
      
   A similar situation to my previous animation is the following:   
   https://www.geogebra.org/m/gbqzyba2   
      
   In the inertial reference frame of the ground, when bodies are still,   
   there is no centripetal force and there is no centrifugal force either.   
      
   During the rotation, the blue centripetal force is activated which is   
   the only force acting on body A.   
      
   Instead, on body B (full of water but with the same overall mass as   
   body A), in addition to the blue force, the red force of the water   
   directed outwards (i.e. in the opposite direction to the centripetal   
   force) also acts.   
      
   In your opinion, is it correct that different forces act on body B than   
   on body A, only because of their different rigidity?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)