Hi there. My question is this: does Google Earth account for uphills/downhills in the landscape and actually measure the route accurately? (i am using tools>ruler>path tool) If not, is there some program that does this? I mean, wouldn't the tool assume that everything is flat and therefore measure the route inaccurately?
Try some geometry. Any failure to account for hills is more than made up for in your error in plotting your exact course.
Say you did an entire 10 mile run up (or down) a 5% grade (I believe Mount Washington is 6-7% average). That means for every 100m run on the horizontal, you've climbed 5m.
The actual distance you ran up the slope is:
(dist)^2 = 100^2 + 5^2 = 10000 + 25 = 10025;
therefore dist = 1000025^(.5) = 100.125m.
Over the course of your 10 mile run, you actually ran 10.0125 miles or 10 miles and 66 extra feet.
Do you need that 66 feet covered in your log book?
wow, really, that's all, are you sure you did that right? (not a dig, it just sounds kinda crazy that if you run for 10 miles, climbing 5m for every 100m, that you would only have run .125m [is that meters or miles]farther.)
And how do percents correspond to degrees? What is a 5% grade in degrees?
He did that right. If you run 10 horizontal miles at 5% grade, you will have gained .5 miles of elevation and the actual distance traveled (the hypotenuse) is 10.0125 miles. I understand your misconception, and I think it is one held by a lot of people, but the math to figure this out is pretty elementary.
A 5% grade means the vertical distance traveled is 5% of the horizontal distance traveled, as Asterix explained. You can use the inverse tangent function to find that a 5% grade is equivalent to an angle of 2.86 degrees.
am here wrote:
wow, really, that's all, are you sure you did that right? (not a dig, it just sounds kinda crazy that if you run for 10 miles, climbing 5m for every 100m, that you would only have run .125m [is that meters or miles]farther.)
And how do percents correspond to degrees? What is a 5% grade in degrees?
2.86 degrees.
http://www.carbidedepot.com/formulas-trigright.asp[quote]am here wrote:
wow, really, that's all, are you sure you did that right?
Just curious, but does the Pythagorean theorem sound at all familiar to you? 'a' squared plus 'b' squared equals 'c' squared?
I thought that was early high school math material.
Do you really care if the OP is familiar with the Pythagorean theorem or are you just being a pompus di*k?
Schoolyard bully wrote:
Do you really care if the OP is familiar with the Pythagorean theorem or are you just being a pompus di*k?
Serious question. I was under the impression that it would be elementary to any high school math curriculum yet he/she apparently expressed surprise at the concept. Maybe they teach different math in the US than in Canada.
Are YOU familiar with the Pythagorean theorem?
It is "elementary" to HS math. The problem is, some of us got out of high school 30 years ago. I haven't used the Pythagorean Theory since then. GPS stuff is really new to us old people. Back in the day, we measured courses with our cars and they weren't accurate. 6 mile races were anywhere from 5.7-6.3 miles!
I also had no idea the difference was so minimal. Thanks for the info and to all you young people- you really can use all that stuff you learn in school!
5^2 + 100^2 = 100.124922...^2
You are right if you are talking about running straight uphill or straight downhill for extended periods of time, however if you are running rolling hills, that can add up to more, how much more, still not much, but more than your straight uphill talk.
adequate Will Hunting wrote:
You are right if you are talking about running straight uphill or straight downhill for extended periods of time, however if you are running rolling hills, that can add up to more, how much more, still not much, but more than your straight uphill talk.
It makes no difference if you go up and then down or any combination of the two. Going 5 miles up 5% and coming back down 5% yields the same result...
show me how this:
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Is nearly equal to this:
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12345 wrote:
show me how this:
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Is nearly equal to this:
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You're bad at math, AND bad at reading. "Wow, hello" is right.
They are right about the slope; although, if you are running on a trail route, the small winding curves, which may be traced over as a straight line on google maps, can easily add up. For an extreme example, let's say your route is a series of perfect alternating semi-circles, yet they are short enough that google traces a straight line through all of them. Since the circumference of a full circel is pi*diameter, then the length you've traveled on the semi-circle is pi*.5 ~ 1.57 times longer than the straight line distance measured by google. Obviously this is an extreme case, although cases where you have a lot of short switchbacks up a long hill could be even more so if not accounted for. You may want to zoom in as close as possible when mapping your route.
The Curves wrote:
For an extreme example, let's say your route is a series of perfect alternating semi-circles, yet they are short enough that google traces a straight line through all of them.
Google only traces what the user inputs. If the user traces a straight line, then that is what Google will plot. If the user traces many perfect semi-circles, then that is what Google will plot (and measure).
Obviously this is an extreme case, although cases where you have a lot of short switchbacks up a long hill could be even more so if not accounted for.
As explained by several posters before, the hill is irrelevant. If you have a lot of switchbacks that you want measured, you need to actually plot them. The fact those switchbacks go up or down a hill only adds a fraction of a percent to your distance.