MHB Train Collision Bird Flight Problem - Week 35 (11/26/2012)

[Jameson]

Two trains travel toward each other on the same track, beginning 100 miles apart. One train travels at 40 miles per hour; the other travels at 60 miles an hour. A bird starts flight at the same location as the faster train, flying at a speed of 90 miles per hour. When it reaches the slower train, it turns around, flying the other direction at the same speed. When it reaches the faster train again, it turns around -- and so on. When the trains collide, how far will the bird have flown?
--------------------

 

[Jameson]

Congratulations to the following members for their correct solutions:

1) MarkFL
2) Sudharaka

Solution (from MarkFL): [sp]The bird will be in flight for the entire time it takes for the trains to reach one another, which is one hour, so the bird will have flown a distance of 90 miles.

*Note - They trains collide in 1 hour since they are 100 miles apart and traveling 40mph and 60 mph, thus each covering 40 miles and 60 miles in the span of 1 hour.*[/sp]