Bonus-bonus question. Time reversal of the problem: The fly is stuck between the two trains standing still on the track when suddenly the trains move apart (with the speeds from before) and the fly flies between them (as before). What is the position of the fly when the trains have returned to their stations?
Den 1:28 lørdag den 5. april 2014 skrev Don Kelly <d...@shaw.ca>: Thanks- In any case, the fly is dead-so is Zeno (and the lawyers of his >time).. > >Don >On 04/04/2014 3:19 PM, Roger Hui wrote: >> A quick check indicates that "terminate" can be used as an adjective. >> Therefore, perhaps a better pun is to say "... it is indeterminate as well >> as terminate for the fly", with the last "a" pronounced as a short a. >> >> >> >> On Fri, Apr 4, 2014 at 2:43 PM, Don Kelly <d...@shaw.ca> wrote: >> >>> Initially I would say that it was going perpendicularly to the track but >>> as it is also in the process of reversing direction at this instant- it is >>> indeterminate >>> as well terminal for the fly >>> >>> Don Kelly >>> >>> >>> On 03/04/2014 2:53 PM, Jose Mario Quintana wrote: >>> >>>> Bonus question: Alright, the fly was flying at the constant speed of 100 >>>> mph the whole time; in which direction was it heading at exact the time >>>> when it was crushed? See below if you give up... >>>> >>>> >>>> >>>> ,.@|.@i. 11 >>>> >>>> 10 >>>> >>>> 9 >>>> >>>> 8 >>>> >>>> 7 >>>> >>>> 6 >>>> >>>> 5 >>>> >>>> 4 >>>> >>>> 3 >>>> >>>> 2 >>>> >>>> 1 >>>> >>>> 0 >>>> >>>> >>>> >>>> In all directions perpendicular to the line in which it was flying before >>>> the crash? >>>> >>>> >>>> >>>> Alright, alright, let us change the question to make it less messy, for >>>> example: the trains are running in still in opposite directions but in >>>> parallel tracks next to each other, the fly is flying in between the >>>> tracks >>>> in the same pattern as before ... (and with all the other necessary >>>> modifications). In which direction was the fly heading at exact the time >>>> when the two trains crossed each other? >>>> >>>> >>>> On Tue, Apr 1, 2014 at 12:59 PM, Roger Hui <rogerhui.can...@gmail.com> >>>> wrote: >>>> >>>> There is a somewhat related anecdote. Two trains are 100 miles apart on >>>>> a >>>>> straight track, facing each other and travel at 25 miles per hour toward >>>>> the other. At the same time, a fly flies at 100 miles an hour from one >>>>> train to the other and, when it reaches the other train, turns around >>>>> instantaneously and flies toward the other train, and so on. When the >>>>> trains crash, what is the total distance the fly flew? >>>>> >>>>> There is an easy way and a harder way to compute the answer. Someone >>>>> posed >>>>> the question to John von Neumann. After a moment, he answered, 200 >>>>> miles. >>>>> >>>>> Correct. Now, Johnny, how did you figure it out? >>>>> >>>>> I summed the series. >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> ---------------------------------------------------------------------- >>>> For information about J forums see http://www.jsoftware.com/forums.htm > >>>> >>>> >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >>> >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > >---------------------------------------------------------------------- >For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
