Bird Flying between TrainsDate: 08/30/97 at 21:57:58 From: Koury Subject: Word problem Two trains are 150 kilometers apart and are heading toward each other along a single track. The first train is going 90 kilometers an hour; the second train is going 60 kilometers an hour. Flying at a constant speed of 110 kilometers an hour, a bird takes off from the head of the first train, flies to the head of the second, immediately turns and flies back to the head of the second, and keeps going like this until the two trains crash. How far does the bird fly? Koury Date: 08/31/97 at 08:45:55 From: Doctor Anthony Subject: Re: Word problem This sort of problem is best done using a little lateral thinking. Since the trains start 150 km apart and have a closing speed of 90+60 = 150 km/hr, they will meet in exactly 1 hour. The bird is flying at a speed of 110 km/hr, so in 1 hour it flies 110 km. Distance flown by bird = 110 km. -Doctor Anthony, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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