How Far Does the Bird Travel Before the Trains Collide?

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Homework Help Overview

The problem involves two trains approaching each other on a straight track, each traveling at 30 km/h, and a bird flying between them at 60 km/h. The original poster is trying to determine the total distance the bird travels before the trains collide, assuming they meet in the middle.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • The original poster attempts to understand how to approach the problem, questioning the assumption that the bird travels until the trains meet. Some participants suggest using a simple formula for distance, while others reference anecdotes about famous mathematicians and their approaches to similar problems.

Discussion Status

The discussion includes various perspectives on how to tackle the problem, with some participants offering insights into the relationship between the trains' speeds and the time until they collide. There is no explicit consensus, but several lines of reasoning are being explored.

Contextual Notes

The original poster expresses uncertainty about the approach to the problem, and there are references to common misconceptions or alternative methods that may complicate the solution.

olilee
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I am having a little trouble starting this problem for physics class.
Two trains, each having a speed of 30 km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 60 km apart and heads directly for the other train. On reaching the other train it flies directly back to the first train, and so forth. What is the total distance the bird travels?
I am assuming that the bird travels till the two trains meet in the middle since their velocity is the same. But I am not sure how to approach the question. Thank you so much in advance for the help.
 
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Yeah it is so well-known :cool:
Just use the simplest formula for distance : you already know one variable, what is the value of the other ?
 
There is a story that tells, Von Neumann has been asked this problem. After thinking for one or two minutes, he gives the correct answer. The other guy very surprised : "Weird ! Usually people try to sum the series instead of using the simple solution !" Von Neumann replies "What simple solution ?" :biggrin:

I hope it's fake. :bugeye:
 
There is an old story that a person asked VonNeumann a problem similar to this. VonNeumann thought for a moment and then gave the correct answer. The questioner laughed and said "Most people start trying to do that as an infinite sum!".
VonNeumann looked puzzled and said "But I did it as an infinite sum!"

For those of us who can't do such sums in our head, there is a much simpler way to do it: the trains are headed toward each other at 30 km/h and so are "closing" on each other at 60 km/h., they will colide after 1 hour. (Another way to calculate that is to argue that since the trains have the same speed, they will meet in the middle {just as you said}- each must cover 30 km at 30 km/h so- 1 hour.)

Now you know the bird will be flying at 60 km/h for one hour. How far will it have flown?
 

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