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Unread 02-05-2014, 16:01
Oblarg Oblarg is offline
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Re: Custom Gearboxes

Quote:
Originally Posted by Tristan Lall View Post
Isn't that only true if you construct the system using dimensionless constants? You can specify that you're looking for ft/s from rev/min, and use dimensions of ft/rev (from the circumference equation, so your π should be included there in the unit conversion) to keep everything consistent.
The whole point of dimensional analysis is usually to do calculations without specific knowledge of the equations governing the system, so doing this sort of defeats the purpose. Clearly one can add a sufficient number of non-physical units (such as "revolutions") and reduce any problem to "dimensional analysis" with enough care, but then you're not really doing dimensional analysis anymore.

Unsurprisingly, you usually only do dimensional analysis when the system is sufficiently complicated that you don't want to solve the problem properly (e.g. estimating the temperature of the sun or the size of the mountains on a planet of a given size).
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Last edited by Oblarg : 02-05-2014 at 16:03.