On page 19, in the discussion of the Adams' first bus ride into Yosemite, it says the bus rose "two thousand feet in ten miles". What was the percent grade of that road?
Monday, April 13, 2009
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On page 19, in the discussion of the Adams' first bus ride into Yosemite, it says the bus rose "two thousand feet in ten miles". What was the percent grade of that road?
Posted by Mr. Z at 8:48 PM
2 Comments:
2000 feet/10 miles =
2000 feet/52800 feet =
20/528 =
5/132 =
(about) 3.8%
This was intended as a simple question relating to some work on percents we have been doing in math. The calculation Ben did shows Rise over Run. However, as he was doing the math I realized the error. The 10 miles traveled does not represent the run. Instead it is the hypotenuse of the right triangle rather then the base. We used what we know about right triangles to find out what the base was. We found that the base was 99.9% of the Hypotenuse. So the answer of 3.8% grade is not substantially different. (3.8% is a rounded number and that does not change if the more accurate base is used.)
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