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B Deepest Hole In The World

  1. May 7, 2016 #1

    just saw an documentary about "the deepest hole in the world" on NG:
    <link to video deleted>
    Can anyone tell what it is, and what is the exact quotation to determine the height
    (with fricton stone-pipe)
    Last edited by a moderator: Sep 4, 2016
  2. jcsd
  3. May 7, 2016 #2


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    hi there,
    welcome to PF

    Sorry but I have a lot of problems believing that video. I suspect some of the sound effects have been added

    here is a wiki link to that is the deepest borehole drilled


    so, if nothing else, the title of that video is false for a start

    Last edited by a moderator: Sep 4, 2016
  4. May 7, 2016 #3


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    Staff: Mentor

    Never, ever was this a fall of about 12km.
    Edit: Seems to be a new record on how fast Murdoch ruined a once excellent tv channel.
    Last edited by a moderator: Sep 4, 2016
  5. May 12, 2016 #4
    If you not to consider resistance forces (like air resistance), then
    ##h=v \cdot(t + \frac{v}{g}- v \cdot \sqrt{\frac{1}{g}\cdot(\frac{1}{g}+\frac{2\cdot t}{v})})≈4100*m≈4*km##
    • h is depth of hole h≈4102.3*m
    • t is time from droping stone until hearing the the stone hit somebody t≈41*s
    • g is gravitational acceleration g≈9.8*m/s2
    • v is speed of sound v≈340*m/s
    It is quite bad approximation, because the stone surely did not go break sound barrier. Real depth is smaller.
    video sound may be fake.
  6. Sep 4, 2016 #5


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    Fake video. Thread closed.
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