From: fortunati.luigi@gmail.com   
      
   What is the difference between the force accelerating the mass (F=ma)   
   and the force deforming the mass (Hooke)?   
      
   Can a force accelerate mass without deforming it?   
      
      
   [[Mod. note --   
   1. Deformation can be quasi-static or dynamic, whereas acceleration   
      is necessarily dynamic.   
   2. That depends on the force and the body-being-accelerated.  If the   
      force is somehow applied equally to each part of the body (e.g.,   
      a uniform gravitational field in the Newtonian perspective), then   
      the body can be accelerated without any deformation.  Or, if the   
      body is either very small or very stiff, and/or the acceleration   
      is very small, then the deformation may be negligibly small.   
      An important limiting case of this is the acceleration of a point   
      mass, which we define as a mass with no internal structure; a point   
      mass doesn't deform under acceleration.  Electrons are a well-known   
      example.  But if a force is applied to a macroscopic body, and is   
      *not* applied equally to each part of the body, then yes, the body   
      will deform.   
   -- jt]]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)