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HomeOff Topics › Another rope one...( plus one for pathogens)
12-08-2004 06:36 PM  13 years agoPost 21
Colibri

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The Netherlands

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Oh boy, this is a difficult one. (Definitely not stupid )

Tim

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12-08-2004 07:15 PM  13 years agoPost 22
Sp00ky

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CHRISTCHRUCH, NZ

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ah donn
I cant beleive you posted that old arse joke in here.

The missus has let me out on good behavior, and ive got new toys I wanna play with.

Sing out over xmas if you wanna hook up

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12-08-2004 09:59 PM  13 years agoPost 23
Colibri

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The Netherlands

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The answer is that we can escape.

If we would start moving in the opposite direction of the goblin he has to walk Pi*R to make half a circle and we have to row R. Since the distance is Pi (3.14) times larger for the goblin but he walks 4 times faster than we can row it is easy to see that we will NOT beat him like this. We will get eaten.

So we have to be smarter and keep an eye on the goblin as we row and always move in such a way that the center of the lake is always between us. Lets assume the goblin moves clockwise and starts north. After the goblin has walked 1/4 circle he ends up east. We now have rowed in a very small half circle path starting at the center and ending west of the centre (still exactly 180 degrees away from the goblin). During this we have always been exactly 180 degrees away from the goblin.

We now have reduced the distance we have to row in a straight line to R-1/4R = 3/4R while the distance the goblin has to walk is still R*Pi.

(In the time the goblin can move 1/4 of a circle we can move half a circle of 1/8th its size, so we are the diameter of a 1/8R circle to the west which is 1/4R)

Lets assume the speed of the goblin is Vg and the speed of the boat is Vb.
We know the goblin moves 4 times our speed so that leads to: 4*Vb=Vg.

The time the goblin takes to walk half a circle is: (Pi * R)/Vg = (Pi * R)/(4Vb)
Our time to go straight to the coast opposite of the goblin is: 3/4R / Vb

So in order not to get eaten we must be there in less time so:
3/4R / Vb < (Pi * R)/(4Vb) or
3/4R < (Pi *R)/4 or
3R < (Pi*R) or
3 < Pi which is true as Pi is 3.14....

So we can make it.

Tim

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12-08-2004 10:47 PM  13 years agoPost 24
rchelipilot121

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Crap!! I'm here again!!

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I agree on this one..not stupid at all. I would also like to appoligize to rchelipliot. I misstook what you said about FF being stupid. I didn't realize that you were cutting on yourself...
Thanks for the apology, pathogens. It takes a mighty big man to say he's sorry. It's very easy to misunderstand things in a forum such as this. I'm very guilty of relying on tone fluxuations and body language to get my point across in daily speech, and you have none of that with typed info. After going back and reading my post I see how it could been mistaken. Please also accept my apology for egging you on.
Now that we are all playing nice.....
This one was very tough. I was off in left field somewhere when I tried it. tvhalter seems correct just from skimming through it. The answer is very long, and due to my slow typing, I'll try to get it posted after while.

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HomeOff Topics › Another rope one...( plus one for pathogens)
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