From: fortunati.luigi@gmail.com   
      
   Tom Roberts il 28/10/2023 18:40:52 ha scritto:   
   >> If inertia is the ability of bodies to resist acceleration (which is   
   >> a vector), then it cannot be a scalar!   
   >   
   > No.   
      
   Maybe you meant to say: yes, because then you write...   
      
   > When a force is impressed upon a massive object, the object's   
   > inertia resists in the opposite direction.   
      
   If you say it resists in the opposite direction, then it is a vector,   
   because only vectors have a direction.   
      
   > So inertial CANNOT be a vector if it is to act the same for   
   > all forces in all directions.   
      
   Inertia doesn't have to act in all directions, it just has to be ready   
   to act in all directions, *before* external forces arrive!   
      
   But when an external force arrives, inertia reacts in only one   
   direction: the opposite one!   
      
   Just like friction does, it is ready to brake in all directions but   
   when activated it only brakes in the direction opposite to the motion.   
      
   Check out my animation   
   https://www.geogebra.org/m/mjnqb8vk   
      
   Before the collision, the body m2 is ready to act in all directions   
   because it does not know from which side the force will come.   
      
   He is ready to act but does not act.   
      
   It is only when the body m1 comes at it from the left that the inertia   
   of the body m2 reacts and it does so in only one direction, the one   
   opposite to the force it receives, i.e. towards the left!   
      
   > Indeed "inertia" is really another name for "mass",   
   > which is clearly a scalar.   
      
   Inertia is not a mass, it is a *property* of the mass which concerns   
   its behavior in the event of an external vectorial intervention.   
      
   Luigi Fortunati.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)