From: edprochak@gmail.com   
      
   On Tuesday, April 3, 2018 at 3:12:35 AM UTC-4, Luigi Fortunati wrote:   
   > Thomas Koenig sabato 31/03/2018 alle ore 14:57:29 ha scritto:   
   > >> 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.   
   >   
   > We are talking about full rubber tires (without gas), and we neglect   
   > temperature variation and centrifugal force.   
      
   Well that neglects the other significant factors, so the answer is   
   simply 3 millimeters.   
      
   OTOH, Thomas pointed out those other factors can have significant   
   and complex effects on the question. So your reply is like   
   asking "if the temperature at 8AM is 32 F what will the   
    temperature be at 1PM? but neglect the sunlight and wind."   
      
   So are you asking for the theory for solving the problem?   
   or the practical (engineering) methods for the effects?   
      
   Ed   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)