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CTK Exchange
HS Greer
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Nov-07-01, 09:27 PM (EST) |
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2. "RE: a walking man and a running dog"
In response to message #0
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This is another version of the problem solved by Von Neuman. 20 miles is correct. The man walks 2.5 hours to go the 10 miles. In 2.5 hours, at 8 miles per hour, the dog runs 20 miles. HS Greer |
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iliaden
Member since Aug-14-05
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Apr-02-06, 10:23 PM (EST) |
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3. "RE: a walking man and a running dog"
In response to message #0
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whenever I encounter such a problem, I always answer 20 miles, yet there is one point on which I am not certain: when the distance between the man and the waterfall is so small that the dog could fit between them, couldn't the dog simply stand still, while touching at both the man and the waterfall, thus running at an infinite speed since it reaches both of it's targets at the same time. Then I guess the answer would be that the dog ran an infinite distance. I perfectly understand that this does not make a lot of sence, yet could you explain me why am I wrong? thanks
Ilia Denotkine |
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Novice
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Apr-17-06, 08:46 PM (EST) |
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6. "RE: a walking man and a running dog"
In response to message #5
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>I disagree. Claiming that a dog that is standing still is "running at an infinite speed" is obviously wrong. I ain't any wiz but I think relativity is the factor. From man point of view, dog is coming to him and vice-versa, I guess.
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JonJonBinks1
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May-03-06, 11:31 PM (EST) |
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7. "RE: a walking man and a running dog"
In response to message #3
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>when the distance between the man and the waterfall is so >small that the dog could fit between them, couldn't the dog >simply stand still, while touching at both the man and the >waterfall, thus running at an infinite speed since it >reaches both of it's targets at the same time. Then I guess >the answer would be that the dog ran an infinite distanceEven if the dog was going at an infinite speed it wouldn't be moving and therefore have a sspeed of zero. Infinity(speed)x 0(distance)=zero I also agree with that guy who said the problem should be inturpurated as the dog and man were both geometric points, in which case there would be no way the dog could be travelling at an infinite speed. |
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