Posers and Puzzles

Posers and Puzzles

  1. Standard membertalzamir
    Art, not a Toil
    60.13N / 25.01E
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    24 Oct '11 09:28
    A flagpole has diameter of 10 centimeters (4"😉. A rope that is 10 meters (30'😉 long has been attached to the top. It spirals around the flagpole 25 times before the other end of the rope reaches the ground. How tall is the flag pole?
  2. Standard memberforkedknight
    Defend the Universe
    127.0.0.1
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    24 Oct '11 14:351 edit
    I get
    Reveal Hidden Content
    25 * sqrt(40^2 - 10pi^2) = ~619cm
  3. Standard membertalzamir
    Art, not a Toil
    60.13N / 25.01E
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    24 Oct '11 14:40
    I wonder why the answer I got is exactly 25 times yours..? And that does make the respectable-sized flagpole I had in mind..?
  4. Joined
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    35068
    24 Oct '11 16:421 edit
    I agree with forkedknight's answer:
    Reveal Hidden Content
    sqrt[L^2 - (25*pi*d)^2]
    ,
    where L = length of rope and d = diameter.
  5. Standard memberforkedknight
    Defend the Universe
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    24 Oct '11 17:102 edits
    Originally posted by talzamir
    I wonder why the answer I got is exactly 25 times yours..? And that does make the respectable-sized flagpole I had in mind..?
    25 times what i got is 15x longer than your rope...

    *edit* I see your response was before I did my edit, and my edit added the multiplier of 25 that i missed in my initial calculation (I broke the flag pole up into 25 rectangles across which the rope makes the hypotenuse)
  6. Standard membertalzamir
    Art, not a Toil
    60.13N / 25.01E
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    24 Oct '11 17:58
    So we both multiplied by 25? That makes a very awesome flagpole. ^_^ So yes, a bit over six meters it is.
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