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Insights A brachistochrone subway is not a cost-effective idea - Comments

  1. May 14, 2015 #1

    rude man

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    Last edited by a moderator: May 14, 2015
  2. jcsd
  3. May 14, 2015 #2

    mfb

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    Where is the point in the circle arcs?
    You know the fastest way to get from A to B in general - let the deepest point of the brachistrochrone be at a depth of h. What is the ideal shape if you want to take a longer distance, but with depth limited to h? Well, just add a straight section in between the brachistrochrone halves. It will run at the maximal possible speed, and you already know the first and last part cannot be faster.

    For the 1600m distance, you need 22.6 s for the curved sections, and 12 seconds for 800m at 66m/s, for a total of 34.6 seconds.
     
  4. May 14, 2015 #3
    Well this was worth reading i learned something interesting today so thanks for writing this.
     
  5. May 14, 2015 #4
    Very unique entry!
     
  6. May 15, 2015 #5

    rude man

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    Good observation. Thanks.
     
  7. May 26, 2015 #6

    rude man

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    Following mfb's observation, the title of my blog should be changed to "Modified Brachistochrone Subway!". mfb has come up with the ideal solution and it resurrects the viability of the Brachistochrone in subway engineering!
     
  8. May 26, 2015 #7
    Interesting topic.
     
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