<PRE><B>Question 466974</B>
two driverless trains race toward each other on the same track; one is traveling at a constant speed of 60 miles per hour and the other at 70 miles per hour. a fly starts at the front of one train and flies toward the second train. when he reaches it, he turns around and flies back to the first train, when he turns around, and so on. the fly maintains a constant speed of 110 miles per hour, losing no time in changing direction. if the trains are now 65 miles apart, how far will the fly fly before he is crushed when the trains collide?
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The trains are converging at (70+60) = 130 mph
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Time to go 65 miles = 65/130 = 1/2 hr.
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The fly will fly (1/2 hr)(110 miles/hr) = 55 miles before being crushed.
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Cheers,
Stan H.
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