From: tkoenig@netcologne.de   
      
   Luigi Fortunati  schrieb:   
   > A stationary machine of 300 kg compresses the tread of its wheels   
   > against the asphalt by 3 millimeters.   
   >   
   > If the same machine is running at high speed (without bumps or jolts),   
   > does the compression of the tires remain the same or decrease compared   
   > to the 3 mm that it had when it stopped?   
      
   The answer is, "it depends".   
      
   Are we talking gas-filled tires or solid tires?  I am assuming   
   some kind of rubber as the material.   
      
   Energy dissipation in the tread will result in higher tread   
   temperature, resulting in lower elastic modulus - the tread will   
   become softer, and the machine will tend to sink down more.   
      
   Heat dissipation will also lead to a higher temperature of the   
   gas filling (if any), which will increase the internal pressure   
   and make the tire harder, so the machine will sink down less.   
      
   Finally, centrifugal force (splease skip the discussion if that's   
   real or not :-).   This will increase the outer diameter   
   of the tire.   
      
   Tires, especially automobile tires, are a well-known and (one   
   hopes) well-understood field of engineering.  I suspect there is   
   ample literature on the subject.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)