Re: Sometimes physics is fun

["J. Green" <green320@RCN.COM>]

> 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.

My goal isn't to achieve maximum acceleration.  My goal is to beat everyone
else and show some creative physics, while maintaining some degree of
safety.  I figure, I'll have someone trigger the start and I'll be at the
end of the track with some kind of pillow or net or something to catch the
thing before someone gets hit or something gets broken.  I figure I'll aim
the co2 slightly upward to have a component normal to the track.

> The only challenge would be to design the thing to remain
> in the general vicinity of the track.

I figure I'll aim the co2 slightly upward to have a component normal to the
track.

> There has been a lot of wild guessing in this thread.

Well, after I do some testing, and I win the race :) , I'll be able to
provide some verified information on the subject.

> 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.

As I said before, I'm looking to participate in a 30ft race with some degree
of safety.  If rocketeers only wanted to go 30ft in the air, maybe they
would use co2 cartridges.

> 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.

Well, I guess I am launching a model rocket horizontally indoors and near
people, but when you put it that way, it sounds kind of bad....

Josh