Inertia

[Richard Brekne]

James Ellis wrote:
> 
> To All,
> 
> I was not aware that there were three different definitions of inertia
> floating around.  I am keenly aware that we are all trying to describe the
> effects of inertia, and the problem is semantics.
> 
> I did not define inertia.  Now I will.  Here goes.
> 
> Inertia is that property of mass which causes it to remain at rest if it is
> at rest, or to remain in motion in a straight line if it is in motion, if
> no force acts upon it, or if all forces that may be acting upon it are
> equal to zero.
> 
> Does anyone disagree with that?  I might be able to refine it a bit, but I
> think that says it.
> 

No I dont think anyone disagrees with that. In fact that general
statement is in virtually everyones posts. As for your next statement,
there only seems to be one or two who contridict that Inertia is
directly proportional to mass.. but.....

> Inertia is directly proportional to mass.  If that's not true, then all my
> old textbooks I have kept these many years are wrong.
> 

....... where I get crossed up with your words is when you say the
following taken from your last post..

"Inertia is a minifestation, a property, an effect, of acceleration and
deceleration.  It's proportional to the square of the change in speed,
or velocity.  Acceleration and deceleration are changes in velocity. 
The velocity, or speed, of a mass revolving about a central point is
proportional to the radius of the orbit of that mass.  Therefore, the
moment of inertia is proportional to the square of the radius, or the
square of the acceleration or decelaration."

If this was not meant as a definition, well ok.. but it sure comes
accross like one.

Do I understand this post then to say that you do not define inertia as
proportional to the square of acceleration ?


> 
> The kids, grand kids, and great grand kids will soon be here for Christmas
> Eve, and I need to go poke the fire and throw another log on it.  I'll see
> you later.
> 
> Merry Christmas,
> 
> Jim Ellis
> 

Well... I hope you have a nice evening with the family. Ours is over
here... Christmas eve was spent with my wifes parents and all their kids
and grandchildren. Lots to eat and drink, lots of songs, and lots of
presents. A wonderful, if rainy Christams eve in Bergen Norway.

Best wishes to one and all !

RicB