Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

[Phys-L] Re: Momentum Agina



Carefully count the degrees of freedom. How hoat does the coupling get?
Regards,
Jack

On Tue, 6 Dec 2005, David Abineri wrote:

Thank to those who responded to my question. May I rephrase it now
thanks to clarifications by several of you?

If a stationary railroad car is struck by a moving railroad car of equal
mass and coupled to it, why is that regardless of the material of which
the cars are made and regardless of their aerodynamics and regardless of
the density of the atmosphere in which they are moving and regardless of
whether there is an atmosphere or not that half the kinetic energy is
lost (converted to other forms)?

To both my students and to me, this does not seem reasonable and yet, if
momentum is conserved and the masses are equal this must happen!

How does one explain to a high school class of bright students why,
regardless of all these factors and some I haven't mentioned, exactly
half the kinetic energy is always lost?

Thanks again, I appreciate your thoughts and I hope the question is more
clear.

David Abineri


--
dabineri@fuse.net


--
"Trust me. I have a lot of experience at this."
General Custer's unremembered message to his men,
just before leading them into the Little Big Horn Valley
_______________________________________________
Phys-L mailing list
Phys-L@electron.physics.buffalo.edu
https://www.physics.buffalo.edu/mailman/listinfo/phys-l