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tlb
2193 days ago
That's incorrect. Power consumption is proportional to drag * speed, and drag is speed^2, so power is speed^3, and energy per mile is speed^2.
3 comments
D_Alex
2193 days ago
Or: Work = Force * Distance, so the energy spent per mile will be proportional to drag force, which is proportional to speed^2.
Either way, its 21% increase in energy consumed per mile in this case.
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btilly
2192 days ago
Ah, shoot. You are right. Energy is force times distance, momentum is force times time. I was thinking about force times time.
wipes egg off of face
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carlob
2193 days ago
True but we're interested in power consumption per distance traveled so it goes back to O(v^2).
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sokoloff
2193 days ago
That’s precisely what the last clause you’re responding to says. You’re agreeing but couching it as a “but”.
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Either way, its 21% increase in energy consumed per mile in this case.