Kresimir Kumericki wrote: > > [sci.physics.research removed] > > In sci.physics Chris Hillman <email@example.com> wrote: > > On 22 Oct 1999, Phillip Helbig wrote: > >> The problem being: Two trains are 60 miles apart and approaching each > >> other at 30 miles per hour. There is a fly flying between the > >> cowcatchers of each train, at 60 miles per hour, back and forth, turning > >> around immediately. What is the total distance covered by the fly
The poster is insufficiently lazy. Draw a Feynman-type diagram; space horizontal, time vertical. The trains' trajectories form a V and the fly travels a shrinking zigzag (limited by the length of the fly!). Measure the path length!