From: julio@diegidio.name   
      
   On Friday, 22 July 2022 at 13:04:58 UTC+2, J. J. Lodder wrote:   
   > [Moderator's note: It seems that all has been said which can be   
   > meaningfully said in this thread. Thus, any future posts must present   
   > something truly new rather than just a repeat (rephrased or not) of   
   > previous exchanges. -P.H.]   
      
   But no agreement has been reached even among those posting   
   answers, indeed here I feel compelled to try and again object/   
   question:   
      
   > Luigi Fortunati  wrote:   
   >> Torn Rumero DeBrak alle ore 15:59:04 di giovedà 21/07/2022 ha scritto:   
      
   > It is an error to call that reaction force 'a centrifugal force'.   
   > THERE ARE NO CENTRIFUGAL FORCES.   
      
   I'd say that is indeed an error, but not for that reason:   
      
   If you hop on a merry go round and don't hold yourself...   
   and then I won't repeat what I have said upthread, but if we   
   actually *measure* the acceleration locally, we do find that   
   there is in a force, a very concrete one: so, to say that   
   centrifugal forces plain "do not exist" is simply wrong and   
   eventually misleading.   
      
   In fact, here is my own summary of the scenarios here:   
      
   In the inertial frame in which -say- a ball is attached to and   
   rotating around a central pivot at rest, there is a *centripetal*   
   force from the ball directed to the center (at every instant),   
   and the reaction is the contrary force pulling the central   
   pivot towards the ball.   
      
   OTOH, in the rotating frame in which the ball is at rest, there   
   is a *centrifugal* force pulling the ball *away from* the central   
   pivot, and the reaction is again the contrary force at the central   
   pivot, i.e. here *away from* the ball.  So, indeed the analogous   
   to the inertial description, but in opposite directions: outwards   
   instead of inwards.   
      
   And now, just to be clear, back to errors and reasons: it is not   
   that centrifugal/centripetal are related by Newton's third law   
   (the error): rather, they exist in distinct frames of reference,   
   and each sees a corresponding reaction as per the third law   
   (the reason).   
      
   No?   
      
   Julio   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)