I have also cleared a "contained flame" ... model rocket motor
Sometimes so-called physics is ridiculously dangerous.
Whoever approved the rules for this exercise is a
candidate for the Darwin award. My recommendation:
-- do not participate.
-- do not attend.
-- advise everyone you know not to attend.
> I'm under the impression that a co2
> cartridge will give me more bang in 30ft than a model rocket motor
> will (which are also made for more than a 30ft run)
The physics is not properly analyzed in terms of what
the devices were made "for".
Also the physics is not properly analyzed in terms of
the length of run. Anything that wins a drag-race of
length X will be able -- indeed inevitably destined --
to go a lot farther than X.
A modest rocket engine will propel a "car" sideways at
well over 10 Gees. It will cross the 30ft finish line
about 1/2 second after departure, with a speed of about
Mach 0.2 or a little less, and will continue to accelerate
for another 1/2 second ... unless it hits something ...
or somebody.
The only challenge would be to design the thing to remain
in the general vicinity of the track.
I doubt that a CO2 cartridge has more specific impulse
than a rocket engine ... otherwise model rocketeers would
use CO2. But it hardly matters: if it is more powerful,
you don't want to be around it, either.
I have no objections to model rockets per se. But when
somebody establishes rules that encourage launching a
rocket *horizontally* and/or *indoors* and/or *near people*
... then well yes, I have objections.