| From: | korishinzo@*****.com (Ice Heart) |
|---|---|
| Subject: | Acceleration and G-force (was Firearm Design : How long does it |
| Date: | Mon, 21 Feb 2005 09:26:03 -0800 (PST) |
> F1-LM...last I read on it, top speed was in excess of 320kph, and
> it's a sportscar....or supercar if you care to go by it's more
> accurate classification, the Porsche Carrera GT which
> is "speculated" to be able to exceed 210mph from the factory line,
> translates to 337.9kph according to the conversion
> tool on my mac. If the same tool is able to do the math correctly,
> which I've no reason to doubt, your average BMW has a governor at
> approx 250 kph when shipped to the US, according to this tool, 300
> kph is 186.41 mph, while MOST sports cars can't do that speed
> reasonably, there are MORE than enough examples of cars that can.
> Most any Ferrari, Porsche, Lamborghini, the Viper, or even the
> Corvette are capable of those speeds with minimal modification if
> any.
I submit to you that mechanical capability may be a bit different
than reasonable (functional) capability. Formula-1 cars, even stock
NASCAR vehicles, have all manner of design requirements to avoid
getting airborne at the speeds they are traveling... on a closed,
angled track. Let me rephrase: No one on an open freeway can hope to
keep a sportscar reliably on the road surface at speeds in excess of
200 miles per hour. I have seen footage of NASCAR vehicles suddenly
flipping into the air, because various precautions to keep the
vehicle aereodynamically pushed against the ground failed. Even a
Formula-1 car has limits to what sort of speeds it can reach and stay
on the track. Sure, I can buy a Porsche whose powerplant and
drivetrain are capable of pushing the vehicle up to 250kph... chances
are very good that somewhere along the way the car's front end will
get lifted off the ground and I'll crash. Furthermore, I don't think
any of those cars can go from 0 to 250kph in 3 or 4 seconds, and even
if the powerplant, drivetrain, and tires could somehow grant that
capability I doubt the vehicle would be controllable under such
acceleration.
I think the problem is that I keep stating as absolutes what really
amount to common sense observations. Yes, many sportscars can
achieve those speeds... with the correct body options to provide
spoilage to keep the car grounded... and a very skilled driver...
under ideal environmental conditions...
That same car and driver on a freeway in the city are NOT going to
achieve those speeds without catastrophic incident. Not likely.
> Again, not to argue to be a pain, but people flying those jets
> don't have anything special that you or I don't have, they're just
> tested for the tolerance to it before being put onto a carrier. Do
> the math for how many G's your average "Top Fuel Dragster" in the
> NHRA Drag Circuit pulls on each quarter mile run, while it may not
> be quite THAT much force, it's definitely a bit, and very few
> people pass out from that force.
excerpt from:
Acceleration of Blackout in Fighter Pilots
The Physics Factbook
Edited by Glenn Elert
"If a force of 4 to 6 g is sustained for more than a few seconds, the
resulting symptoms range from visual impairment to total blackout."
"The human threshold is around +7.5 G's, for a trained pilot in a 'G
suit.'"
"An important figure to remember here is that an average person will
black out if the "headward"acceleration s/he experiences reaches 2 g.
By comparison, people can withstand accelerations on the order of 10
g in directions perpendicular to their bodies without any permanent
adverse effects,..."
Theme park rides are usually kept at around 3g, according to my
research; and capped at 4g, beyond which average adult humans are
expected to suffer blackout.
I have had karate students complain of "head rush" feelings and
dizzyness during jump kick drills, where the "headward" acceleration
is about 2 g, so I can corroborate this fact from a hands-on
perspective. I'd say that a trained pilot in a G-suit is NOT an
"average joe". Most of us could not tolerate even 3 seconds at 6 g
withoiut blacking out. Going from 0 to 70 m/s in 1 second (assume
constant acceleration over Turn, 0-210 in one Turn) is about 7 Gs.
> ...and therefore, it's your duty as a GM to simply look at the
> person and say "no"
Herein lies the problem. The player did not want to hear "no".
After all, the book clearly stated that his vehicle had an
acceleration rating of 14 (IIRC), and a top speed of 400 (something
or other). He had enough successes on his accleration test to make
it work. So why not? My explanation that the physics of his
attempted feat were in a word, ridiculous, fell on deaf ears. He was
determined to do it and wanted me to let him. He had paid for
"modified" tires and improved handling, and felt that those would
compensate for what he was trying to do. Rather than be arbitrary,
as I have been accused of, I gave him a very simple couple of dice
rolls to attempt the impossible. First, roll Willpower (TN of
G-force) to stay conscious. He got zero successes. Second, roll
Body to survive the crash. He failed to stage damage down at all.
In retrospect I should have made the blackout damage affect his Stun
monitor, called it 7D (Stun) instead of just making him black out.
The end result would have been the same, but the game mechanics would
have been more consistent.
> I apologize if I've come across as rude or overly critical, and I
> don't mean to in any stretch of imagination.
See, I'm not at all offended. It takes things like "...you might
want to run the numbers before you arbitrarily kill a character next
time..." to offend me. :)
======Korishinzo
--giving an idiot a fighting chance to survive his own stupidity is
NOT arbitrary, it is fragging generous
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