Re: [Phys-L] force, momentum, torque, and angular momentum

[brian whatcott <betwys1@sbcglobal.net>]

Suppose that force along some axis  is proportional to some material 
constant multiplied by the change of length of material along that axis 
and by the cross section area through which that force is transmitted: 
you might say the force flows through any confection of numerous linked 
materials  in tandem.   Does it help to know that the product of mass 
and acceleration determines that force? Could we say that the 
transmitted force implies that when transmitted via small masses, say 
piano wire, the associated acceleration is greater? Evidently not. I 
suspect a similar line of thought would apply to' flowing momentum'.

Brian Whatcott    Altus OK

On 7/23/2013 10:42 AM, curtis osterhoudt wrote:
> I think it's a quite good document, including the idea of introducing bivectors. At my University, one of the mathematics faculty is excited about introducing bivectors (and much of G.A.) in cooperation with the physics department. Now, we just have to get the high-powered engineering dept. on-board with the whole scheme...
>
> One conceptual problem I *suspect* students will have with the idea of momentum flow as it's presented is the following (I think I can state it as two very intimately entwined concepts, but will let others disentangle these): "If an equal flux of momentum is simultaneously moving from one car, through each bit of string, and through each of the intermediate O-rings, then why aren't the low-mass strings moving very quickly, the larger-mass O-rings moving more slowly, and the large-mass railroad cars moving comparatively slowly? Why doesn't the whole shootin' match break apart? Is this some sort of 'momentum-density-per-unit-length thing?"
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> ________________________________
>   From: John Denker <jsd@av8n.com>
> To: Phys-L@Phys-L.org
> Sent: Tuesday, July 23, 2013 6:26 AM
> Subject: Re: [Phys-L] force, momentum, torque, and angular momentum
>   
> [...]
>
> If you think there are any "more complex problems/concepts"
> that are inconsistent with my definition of flow, please
> explain.  Examples would be particularly helpful.  Please be
> as specific as possible about the nature of the inconsistency.