Re: [Phys-l] internal/external conservative/nonconservative forces!?!?

[William Robertson <wrobert9@ix.netcom.com>]

By that reasoning, then virtually all properties of objects do not  
belong to the objects, given that their values are frame dependent. In  
one sense, I would agree with that statement given that all physics  
constructs are pretty much in our brains. But in a practical sense,  
one that we use in educating students, objects do have properties.

Bill




On Dec 15, 2010, at 3:25 PM, Carl Mungan wrote:

> Bill Robertson wrote:
>
> > If I read you correctly, then it's okay
> > to say that the kinetic energy of a moving object resides somewhere
> > besides in the object.
>
> I'm stealing John Mallinckrodt's thunderbolt, but I would agree that  
> KE of a moving object cannot be ascribed to the object alone.  
> Reason: speed of an object is NOT an intrinsic property of an  
> object. It is RELATIVE to some frame of reference (hopefully  
> inertial in the present case). That frame of reference is presumably  
> attached to some other object (like the earth). If I switch to  
> another inertial frame moving relative to the first frame, the KE  
> "of the object" just changed, even though I didn't change anything  
> about the object! Doesn't that mean the KE is NOT a property that  
> "resides in" (belongs to) the object alone?
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