On Tuesday, August 7, 2018 at 2:04:43 AM UTC-5, John Heath wrote:   
   >   
   > This is an interesting question. Yes a little friction in the scales   
   > could lead to a hysteresis in the measurement for 83.2 vs 82.5   
   > Kg. However this is a thought experiment for the theoretical results so   
   > perfect scales may be assumed as well as zero change in gravity   
   > gradient.   
   >   
   > Under ideal condition of constant speed up and down how much does one   
   > weigh. Let us call the weight 100 pounds for an even number and the   
   > down and up speed 9 meters per second. If the elevator were to   
   > accelerate at 9 meters per second squared then the weight should be 0   
   > pounds moving down and 200 pound moving up. However the elevator is not   
   > accelerating rather moving at a constant speed of 9 meters per   
   > second. This makes for a complicated mix of a nonlinear gravity falling   
   > rate of 9 meters per second squared with linear constant speed of 9   
   > meters per second. With this in mind the down trip weight over time   
   > should be 0 10 99 99.9 99.99 ... pounds. The up trip should be 200 190   
   > 101 100.1 100.01 ... pounds. Its weight would depend on when it is   
   > measured. Note there is an energy conservation concern the numbers   
   > given. The energy up must equal the energy down and 101 up does not   
   > equal 99 down ,, what went wrong ?   
      
   As long as the elevator is moving at a constant speed, whether it   
   is up or down, the weight of the man will be 100 lbs. The only   
   complication is if you consider that the gravitational field varies   
   with altitude, but if the two measurements are made at the same   
   altitude the results will be the same. The differing results Luigi   
   reports are due to experimental errors. There is no theoretical   
   basis for such a variation.   
      
   Rich L.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)