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Old 11-06-2010, 09:07 AM   #12 (permalink)
RobertSmalls
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Quote:
Originally Posted by Boreas View Post
Is the term g ,in the rolling resistance equation essentially one, on the on the surface of earth. With minor variations due to elevation that are small enough to be ignored for fuel economy purposes?
g, acceleration due to gravity, varies in a minuscule fashion with elevation. Variations in the strength of the Earth's gravitational field at its surface are generally of interest to physicists, but not engineers. g=9.8m/sē will get you two significant figures, which is more than you have for the rest of your inputs anyway.

>Is wind resistance an exponental equation due to the v squared term and the rolling resistance equation linear with constant slope due to v or no other them being squared?

I'm not clear on what you're asking here. The force of aero drag rises exponentially with speed, while rolling resistance... well, see the graph I just posted. According to the simplified model, it's independent of speed.
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