Re: A question on inelastic relativistic collisions

[Bob Sciamanda <trebor@VELOCITY.NET>]

Hi Ed,
            I have not looked into the relativistic case, but in my Mech
class I always show that in the Newtonian model the amount of kinetic energy
lost or gained (the Q) in an inelastic collision is an invariant with
respect to a Galilean transformation to another inertial frame.  (That's
why, for example,  in all inertial frames the totally inelastic collision is
that in which the two final velocities are equal -  and in the CM frame all
the kinetic energy is lost and the final velocities are zero.)
You have provoked me to look into the relativistic case, when time allows :)

Bob Sciamanda
Physics, Edinboro Univ of PA (ret)
trebor@velocity.net
http://www.velocity.net/~trebor

-----Original Message-----
From: Ed Schweber <edschweb@IX.NETCOM.COM>
To: PHYS-L@LISTS.NAU.EDU <PHYS-L@LISTS.NAU.EDU>
Date: Wednesday, February 17, 1999 11:06 AM
Subject: A question on inelastic relativistic collisions


> Ed Schweber (edschweb@ix.netcom.com)
> Physics Teacher at The Solomon Schechter Day School, West Orange, NJ
> To obtain free resources for creative physics teachers visit:
> http://www.physicsweb.com
>
> Hi gang:
>
>   The problem with the week long February break many schools have, besides
> that it wastes class time, is that it gives us teachers too much time to
> think.
>
>   Anyway, I was wondering: Since in special relativity, momentum and
energy
> are merged into a single four vector whose components will be different for
> different moving observers, does that mean that the amount of heat lost in
> an inelastic collision is relative to the observer?
>
>   If so, what does that do to specific heats and latent heats. Do these
> also become relativistic quantities?
>
>   What about Kelvin temperature. Is that absolute or relativistic? Kelvin
> temperature is proportional to the average KE per molecule and would not
> that average KE be relative to the motion of the observer?
>
>  Thanks in advance for any input and I promise in the future that I will
> stop trying to think.
>
> Ed Schweber