Puzzle time - Loose laces at the airport
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I assume there's a general answer to the question other than "it doesn't matter", only because the speed of the walkway as compared to the walking speed are not specified and don't matter. Neither is how long tying the shoes take as compared to time on the walkway specified, so that can't matter either. Given a reductio of the time to tie shoes equalling the time it takes for the walkway to move its whole distance, i.e. starting to tie the shoes as soon as your on the walkway and finishing when the walkway is done, the answer to that question is that you should tie them on the walkway. So this specific can probably be safely generalized. I think it has to do with extending time on the walkway. Time spent tying shoes off the walkway is truly wasted.
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@Loki said in Puzzle time - Loose laces at the airport:
I once had a guy warn me that if I passed him he would break my face. I said I am sorry sir and put my head down. Never mess with an insane person.
Larry made you call him sir?!
That is unusual.
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Related puzzle:
You've just poured yourself a cup of coffee and were just about to add milk when you noticed you had to do something urgently for 5min before you can drink the coffee.
If you want to maximize the temperature of the coffee when you finally drink it, should you add the (cool) milk now or just before drinking?
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@Klaus said in Puzzle time - Loose laces at the airport:
Related puzzle:
You've just poured yourself a cup of coffee and were just about to add milk when you noticed you had to do something urgently for 5min before you can drink the coffee.
If you want to maximize the temperature of the coffee when you finally drink it, should you add the (cool) milk now or just before drinking?
Just make sure to tie your shoelaces before u run off to the bathroom (or something otherwise urgent) or you will trip and spill the hot coffee on your pants and end up getting a second degree burn on the dong, which will make your plane trip out of ohare very uncomfortable.
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@Klaus said in Puzzle time - Loose laces at the airport:
Related puzzle:
You've just poured yourself a cup of coffee and were just about to add milk when you noticed you had to do something urgently for 5min before you can drink the coffee.
If you want to maximize the temperature of the coffee when you finally drink it, should you add the (cool) milk now or just before drinking?
Depends on how cold the milk is relative to ambient temperature. If the milk is already at or close to ambient temperature, add the milk now. Strategy is to take advanced of the fact that heat transfers at a slower rate when coffee is closer to ambient temperature.
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I never circled back here.
Horace is right, tie them on the walkway.
For an intuitive answer, imagine walking with your friend together. Right when you get up to the walkway, but before you step on, you stop to tie your shoes. Your friend takes that one extra step and ties them on the walkway. 10 seconds later (say) you both finish and start walking again at the same speed. You’ll never catch up.
Interestingly, this problem came from Terrance Tao.
https://terrytao.wordpress.com/2008/12/09/an-airport-inspired-puzzle/
Best comment:
I asked myself exactly the same questions the first time I was in an airport, namely when I was 15. So, once in my life, I can say I have investigated and solved a mathematical problem in which Terence Tao was also interested, before he did
DON’T let them eat cake.
- RFK Jr -
@jon-nyc That makes sense, but if you tie your shoe, you will finish before your friend.
(Even so, I do understand why you would not catch up)
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Because the two people basically start and stop tying their shoes at the same time (a fraction of a second apart). But in the interim the guy who stopped on the moving walkway was moved along during the time they both tied their shoes. Therefore when they start back up again (at essentially the same time) there’s a gap between them. It never closes because at this point they’re both on the walkway and both walking the same speed
DON’T let them eat cake.
- RFK Jr
