From: richalivingston@gmail.com   
      
   On Thursday, December 29, 2022 at 1:29:17 AM UTC-6, Luigi Fortunati wrote:   
   > Are the rotations (and accelerations in general) all of the same type   
   > (that is, are they all real) or are there real ones and also apparent   
   > ones?   
      
   Luigi,   
      
   I believe you are understanding it correctly.  In a rotating reference   
   frame there are two types of accelerations:  true accelerations and false   
   or coordinate accelerations.  The true accelerations are the same as would   
   be calculated in an inertial reference frame.  The false or coordinate   
   accelerations are the result of the coordinate points following a curved   
   path in the inertial reference frame.  Coriolis forces are in the category   
   of a coordinate acceleration.   
      
   You can find the math on the web, but the general idea is that in a   
   rotating reference frame when taking derivatives of the coordinate   
   positions of an object you have to take into account not only how the   
   object is moving wrt the reference frame, but also how the reference   
   frame coordinates are moving wrt an inertial frame, i.e. rotations.  The   
   accelerations of the coordinate positions have to be subtracted from the   
   calculated accelerations (i.e. second derivative of the coordinate   
   positions) in order to get the "real" forces on the object.   
      
   Rich L.   
      
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