Re: [Phys-L] inertia and the tablecloth demo

[Bernard Cleyet <bernard@cleyet.org>]

> On 2016, Aug 17, , at 14:34, John Denker <jsd@av8n.com> wrote:
>
> > inertia is part of our language and seemingly ingrained in our 
> > physics traditions.
>
> I had what might be called a non-traditional education.  I never ran
> across "inertia" in a physics context until long after I was out of
> school.
>
> The Feynman lectures use the idiomatic expression "the principle of
> inertia" on two occasions to refer to the first law, and otherwise
> don't mention inertia at all.  Certainly there is no attempt to
> quantify the inertia the way we quantify mass or momentum.


I’ll cheque my Feynman et alii substitute, Eisberg and Lerner, for the use of inertia.  



On 2016, Aug 17, , at 13:54, Richard Tarara <rtarara@saintmarys.edu> wrote:

 I think one can substitute momentum for inertia in most physics contexts even when mass might seem more appropriate keeping in mind that a body at rest has zero momentum.  I admit to still being confused in the relativistic realm though when momentum seemingly can't be separated into mass and velocity, but am resigned to the fact that this is the modern approach of most.


Now I am confused:  I thought inertia was synonymous w/ mass. 


bc