SOLUTION: Barry runs up the down escalator in 9 seconds. He can run down the down escalator in 6 seconds. The escalator is 36 feet long. How fast is the escalator moving? Find Barry's speed
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-> SOLUTION: Barry runs up the down escalator in 9 seconds. He can run down the down escalator in 6 seconds. The escalator is 36 feet long. How fast is the escalator moving? Find Barry's speed
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Question 410926: Barry runs up the down escalator in 9 seconds. He can run down the down escalator in 6 seconds. The escalator is 36 feet long. How fast is the escalator moving? Find Barry's speed running down the escalator when it isn't moving. Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Barry runs up the down escalator in 9 seconds.
He can run down the down escalator in 6 seconds.
The escalator is 36 feet long.
How fast is the escalator moving?
Find Barry's speed running down the escalator when it isn't moving.
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Down escalator DATA:
time = 6 seconds ; distance = 36 ft; rate = 36/6 = 6 ft/sec
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Up escalator DATA:
time = 9 seconds ; distance = 36 ft. rate = 36/9 = 4 ft/sec
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Equations:
Barry rate + stair rate = 6 ft/sec
Barry rate - stair rate = 4 ft/sec
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Add to get:
2*Barry rate = 10 ft/sec
Barry's rate when escalator is not moving = 5 ft/sec
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Cheers,
Stan H.
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