1. Standard membereldragonfly
    leperchaun messiah
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    19 Jul '08 21:35
    Originally posted by geepamoogle
    Why then, does it seem to be relatively common that a number of others seem to understand the problem as the poser intended it, but you usually seem to misunderstand the problem and think it poorly worded?
    Wrong geep, you're a liar. There are others who have agreed with me, even on this thread, that take exception to the wording of the problem.
  2. Standard membereldragonfly
    leperchaun messiah
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    19 Jul '08 21:44
    Originally posted by geepamoogle
    I would also suggest to you that a beach ball on a string would not float a foot above the water like a flower on a stiff stem would, but that is tangential to the matter at hand.
    Well then you could add a float, but whatever just as equally contrived i guess. But this idea of the flower on the pond sticking up a foot with it's stem cut exactly at water level that just stretches out exactly to the edge of the pond as long a you use a 5 foot stick just looked so implausible and all that just looked so bogus, PBE6 could only add childish ad hominems to his problem description instead of taking a real interest in it. He could have just thrown some measurements at us without all this silly hokum attached.
  3. Standard memberAThousandYoung
    or different places
    tinyurl.com/2tp8tyx8
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    20 Jul '08 00:25
    Originally posted by eldragonfly
    Well then you could add a float, but whatever just as equally contrived i guess. But this idea of the flower on the pond sticking up a foot with it's stem cut exactly at water level that just stretches out exactly to the edge of the pond as long a you use a 5 foot stick just looked so implausible and all that just looked so bogus, PBE6 could only add chi ...[text shortened]... in it. He could have just thrown some measurements at us without all this silly hokum attached.
    Why don't you offer up a "well worded" problem? By the way, bud, string does not stay straight. It's not rigid, but it bends and twists, so your idea is just as bad.
  4. Standard memberAThousandYoung
    or different places
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    20 Jul '08 00:29
    Originally posted by eldragonfly
    Well then you could add a float, but whatever just as equally contrived i guess. But this idea of the flower on the pond sticking up a foot with it's stem cut exactly at water level that just stretches out exactly to the edge of the pond as long a you use a 5 foot stick just looked so implausible and all that just looked so bogus, PBE6 could only add chi ...[text shortened]... in it. He could have just thrown some measurements at us without all this silly hokum attached.
    Clearly you think the solution offered is going to be wrong on the order of feet, not just inches, since the number given is in feet. Right?

    For someone as critical as you about wording, you need to work on your English too.
  5. Standard membereldragonfly
    leperchaun messiah
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    20 Jul '08 01:45
    thanks for the insightful and endearing post. 😕
  6. Joined
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    20 Jul '08 03:25
    easier to admit you're the only one who doesn't get the problem than make all this hassle.
  7. Standard memberPBE6
    Bananarama
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    20 Jul '08 06:311 edit
    eldragonfly is the worst kind of troll. The greatest contribution he makes to this forum is the excessive amount of horse manure that drops directly from his brain to his fingertips - it keeps plants stems like the one in the original question nice and taught.

    Question #2, for eldigglestick:

    A conga line of length L is dancing forward with speed V1. The last partier in the conga line suddenly remembers that he let the first partier in the conga line hold his drink while he went to the loo, and he wants it back. The last partier runs to the front of the line with speed V2 (which is faster than V), grabs his drink and turns around in a negligible amount of time, and runs back with the same speed V2 to join the line in his original position.

    How far did the first partier move in the time it took for the last partier to get his drink and return to line?

    PS This is a very easy question. If you want an undergraduate engineering level question, I can provide one of those too, although I'm afraid eldickinfly won't be able to solve it because they all REQUIRE THAT YOU STATE YOUR ASSUMPTIONS!!! 😲
  8. Eternity
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    20 Jul '08 17:15
    Originally posted by SwissGambit
    Insufficient intelligence.
    Could not have put it better myself.
  9. Standard membereldragonfly
    leperchaun messiah
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    20 Jul '08 20:371 edit
    nevermind
    nevermind
  10. Standard membereldragonfly
    leperchaun messiah
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    20 Jul '08 20:372 edits
    Originally posted by PBE6

    A conga line of length L is dancing forward with speed V1. The last partier in the conga line suddenly remembers that he let the first partier in the conga line hold his drink while he went to the loo, and he wants it back. The last partier runs to the front of the line with speed V2 (which is faster than V), grabs his drink and turns around in a negligible ...[text shortened]... first partier move in the time it took for the last partier to get his drink and return to line?
    my first guess is to redefine the problem as two objects travelling towards each other at different velocities; one from one of the end points at velocity V2 of Line A which is 2L in length, and one from the other endpoint of Line A, at velocity V1. Since the actual rate/velocity of both objects is unknown, it is impossible to determine where these two objects would meet, or in the case of the congo line, how far it moved.
  11. Standard membereldragonfly
    leperchaun messiah
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    20 Jul '08 22:03
    Originally posted by eldragonfly
    my first guess is to redefine the problem as two objects travelling towards each other at different velocities; one from one of the end points at velocity V2 of Line A which is 2L in length, and one from the other endpoint of Line A, at velocity V1. Since the actual rate/velocity of both objects is unknown, it is impossible to determine where these two objects would meet, or in the case of the congo line, how far it moved.
    Actually since you are not given V1 there is no solution.
  12. Joined
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    20 Jul '08 23:401 edit
    Originally posted by PBE6
    Question #2, for eldigglestick:

    A conga line of length L is dancing forward with speed V1. The last partier in the conga line suddenly remembers that he let the first partier in the conga line hold his drink while he went to the loo, and he wants it back. The last partier runs to the front of the line with speed V2 (which is faster than V), grabs his drink a ...[text shortened]... irst partier move in the time it took for the last partier to get his drink and return to line?
    The solution to this one is a formula, rather than a number.

    It is, in essence, a general case scenario.

    So the congo line is L ft long and moving forward at V1 ft per second.

    The fellow at the end fetching his drink moves at V2 ft per second, a velocity we are told is faster than V1 (or else he'd never catch the front of the line.

    So now, we can divide the calculations into 2 parts.

    Fetching the Drink
    Our hero gains on the front of the line based on his relative speed compared to the line. The velocity is equal to the difference in velocities given.

    Time taken = L / (V2 - V1)
    Line travels = V1 * Time Taken

    Returning to the Back
    Our hero, having succeeded in his quest returns to his position at a relative speed equal to the sum of the two velocities, since they are moving in opposite directions now.

    Time taken = L / (V2 + V1)
    Line travels = V1 * Time Taken

    Now to add the two together and simplify..

    L / (V2 - V1) + L / (V2 + V1)
    Find a common denominator.
    L * (V2 + V1) / (V2^2 - V1^2) + L * (V2 - V1) / (V2^2 - V1^2)
    Combine terms and distribute..
    L * (V2+V1 + V2-V1) / (V2^2 - V1^2)
    Simplify the numerator..
    2 * L * V2 / (V2^2 - V1^2)

    And you have the formula for how long it takes for our hero to complete his mission and return with his drink.

    Now multiply by V1 to find out how far forward the line has moved.

    Answer = 2*L*V1*V2 / (V2^2 - V1^2)
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