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, the bird flies directly back to the first train, and so forth. (We have no idea why a bird would behave in this way.) What is the total distance the bird travels before the trains collide?
Two methods: 1) Sum up an infinite series, which could be a pain... and i'm not quite sure how to do that :D OR.... 2) figure out the time (t) it will take the trains to collide, and multiply by the bird's speed: Distance = Speed * Time Since they both travel 30 km towards each other, they would close a 60 km gap in an hour. Since the bird takes off when the trains are 60 km apart, we can assume it will take the trains 1 hour to collide. The bird flies 60 km an hour so: Distance = (60 km/h) (1 h) Distance = 60 km
cool thanks
omg that question was basic LOL....pellet that is terrible...lol damn physics...
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