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Old 09-07-2008, 01:24 AM   #34 (permalink)
jamesqf
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Quote:
Originally Posted by rmay635703 View Post
Yes but that isn't the whole story. You saw the drag doesn't scale comment? Right?
I saw the comment, but I don't think I really understand what was meant. For practical purposes, cars, trucks, and trains are at pretty much the same scale.

In any case, I didn't say that those two points were the whole story, but they are a big part of it. Take your semi, mount railroad wheels on it, and see how much more it's able to pull. Or consider some of the early "railroads" that were powered by animals, or even humans. The whole point was to reduce rolling friction losses by running on smooth rails.
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