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Re: [Phys-L] heat content



Clarification:

On 02/16/2014 09:02 PM, I wrote:

But not every interesting system is a control-mass system.

....

As another example: In aerodynamics, it is exceedingly common (and
useful) to define the KE of a parcel of fluid in the frame comoving
with the aircraft ... which is not even remotely the center-of-mass
frame.

I derailed the context and conflated two separate ideas.

I meant to say that EVEN IF we treat the parcel as a control mass,
we usually do it in the frame comoving with the aircraft ... which
is not even remotely the center-of-mass frame.

Then, if we analyze things using the control-volume approach, we
are *two* jumps removed from assuming that everything is a control
mass and that the center-of-mass KE is the only KE that matters.