F1GP does not _really_ support gravity - bring the car to a halt
on the hill either side of Eau Rouge at Spa to see what I mean - it
doesn't appear to roll (I think - I could be eating my words soon!).
--
>>>AND if F1GP does not have gravity, then WHY is your car terribly slow at
>>>the start of a 100% race, compared to the speed at the start of a, say,
>>>10% race?!? EXPLAIN THIS TO ME!! You little piece of Papyrus lover!!
>>Oops... someone wasn't paying attention in Physics class. Don't confuse
>>gravity and inertia. Bodies at rest and in motion and all that other
>>tricky stuff that, it seems, is best left to the simulator programmers.
>>Gravity has little to do with it (apart from traction).
>>--
>>Stephen Ferguson
>Gravity HAs a lot to do with it, in this case, the gravity of your fuel
>tank!
The reason cars are slow(in terms of lap times) at the start of the race is because
they have a large inertial mass - which means they are harder to make accelerate.
If one was racing spaceships in zero gravity, the same phenomenon would occur:
lap times (round our space track) would become faster as the spacecraft
became lighter (in terms of their inertial mass).
Their weights would remain zero.
--
Paul Smyth, Dept of Medical BioPhysics, University of Manchester.
Telephone: +44 (0161) 275 5157
>>AND if F1GP does not have gravity, then WHY is your car terribly slow at
>>the start of a 100% race, compared to the speed at the start of a, say,
>>10% race?!? EXPLAIN THIS TO ME!! You little piece of Papyrus lover!!
>Oops... someone wasn't paying attention in Physics class. Don't confuse
>gravity and inertia. Bodies at rest and in motion and all that other
>tricky stuff that, it seems, is best left to the simulator programmers.
>Gravity has little to do with it (apart from traction).
>--
>Stephen Ferguson
>"The gravity of your fuel tank"? You'd have a hard job even
>measuring that! Take a physics course, JJ!
My question, then, is will GP2 allow for alternative values of g so that we
can simulate formula one racing on other planets? How could anyone call this
new program complete without this all-important feature? Beyond this, it had
better simulate alternative atmospheric pressure and chemical constituients as
well (to simulate F1 on jupiter or venus) or else I ain't buying it!
now back to my gravity-wave research...
-------------------------------------------------------------
Michael F. Hundley
Santa Fe, New Mexico USA
-------------------------------------------------------------
Austin, Tx
============================================================
Scott Pruett 1996 PPG Cup Champion!
============================================================
: AND if F1GP does not have gravity, then WHY is your car terribly slow at
: the start of a 100% race, compared to the speed at the start of a, say,
: 10% race?!? EXPLAIN THIS TO ME!! You little piece of Papyrus lover!!
One explanation could be programmed "drag" not gravity. If there was
gravity the car should roll down a hill of its own accord (brake off --
no throttle).
--
**************************** Michael E. Carver *************************
Upside out, or inside down...False alarm the only game in town.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=<[ /./. [- < ]>=-=-=-=-=-=-=-=-=-=-=-=-=-=
>>>>AND if F1GP does not have gravity, then WHY is your car terribly slow at
>>>>the start of a 100% race, compared to the speed at the start of a, say,
>>>>10% race?!? EXPLAIN THIS TO ME!! You little piece of Papyrus lover!!
>>>Oops... someone wasn't paying attention in Physics class. Don't confuse
>>>gravity and inertia. Bodies at rest and in motion and all that other
>>>tricky stuff that, it seems, is best left to the simulator programmers.
>>>Gravity has little to do with it (apart from traction).
>>>--
>>>Stephen Ferguson
>>Gravity HAs a lot to do with it, in this case, the gravity of your fuel
>>tank!
>Hold it right there!
>I think you need the difference between inertial mass and weight explained to you.
>Inertial mass is the degree to which an object can be accelarated by a force. This
>quantity has got NOTHING AT ALL to do with gravity.
>Weight - the force downwards on an object in a gravitational field - is just that -
>it is dependant on both the mass AND the magnitude of the gravitational field.
>The reason cars are slow(in terms of lap times) at the start of the race is because
>they have a large inertial mass - which means they are harder to make accelerate.
>If one was racing spaceships in zero gravity, the same phenomenon would occur:
>lap times (round our space track) would become faster as the spacecraft
>became lighter (in terms of their inertial mass).
>Their weights would remain zero.
>> Mass=slow, that's why your car is slow at the start of a 100% race,
>>and fast at the end (if you didn't***up your tires of course...)
>>AND if F1GP does not have gravity, then WHY is your car terribly slow at
>>the start of a 100% race, compared to the speed at the start of a, say,
>>10% race?!? EXPLAIN THIS TO ME!! You little piece of Papyrus lover!!
>Oops... someone wasn't paying attention in Physics class. Don't confuse
>gravity and inertia. Bodies at rest and in motion and all that other
>tricky stuff that, it seems, is best left to the simulator programmers.
>Gravity has little to do with it (apart from traction).
To add a little more into this stew. . . One of the major
disappointments I had with F1GP was that there was no need to change
gearing when going up a steep incline. In the real world, more
power is needed to go up a hill and less is needed to go down one. Both
ICR's and NASCAR included this bit of physics in their modeling.
Example: the climb to the corkscrew at Laguna Seca. And I too miss the
affects of curbing in these simulations. I also miss the turbo on my
"real" car, but hell you can't have everything . . . Where would you put
it?! (Thank you S. Wright)
Now I have heard that there is no such thing as gravity, that the earth
"sucks". I won't go as far as to say that F1GP doesn't have gravity,
but that it sucks. That wouldn't be nice and of course would start a
huge flame war. (For the humor impaired, this is a pun -- no slam is
intended. I still have my copy of World Circuit/F1GP and I look forward
to checking out F1GP2.)
--
**************************** Michael E. Carver *************************
Upside out, or inside down...False alarm the only game in town.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=<[ /./. [- < ]>=-=-=-=-=-=-=-=-=-=-=-=-=-=
: >A nice balanced view as always, I see. <g>
: You know me...!!
: But really, imagine having the impertinence to question His Eminence Sir
: Geoff Crammond and the second coming of his only child (GP2) who is
: descending to earth in order to save his people from driving Indycars in
: circles.
Wait a minute. . . Okay, you seem to be tipping the balance a little...
ICR2 has 15 tracks -- Of these only 5 are ovals. And a couple of these
are very, very difficult ovals. Sometimes I think those who do protest
the most have something to hide. I find that Indycar drivers are a
little more rounded in that they handle at least 2 different disciplines
in their art/sport. Being able to handle both demanding road circuits
and ovals requires a broader driving discipline. The other reason for
ovals, is that it gives the attending fans a better chance to see more
of a race than sitting at 1 corner or straight on at a road circuit.
________________
| /\ |
| / \ |
V / \ V
/ \
Okay, things seem to balanced a little bit better now. Thank you for
your consideration and time...
--
**************************** Michael E. Carver *************************
Upside out, or inside down...False alarm the only game in town.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=<[ /./. [- < ]>=-=-=-=-=-=-=-=-=-=-=-=-=-=
>>>>AND if F1GP does not have gravity, then WHY is your car terribly slow at
>>>>the start of a 100% race, compared to the speed at the start of a, say,
>>>>10% race?!? EXPLAIN THIS TO ME!! You little piece of Papyrus lover!!
>>>Oops... someone wasn't paying attention in Physics class. Don't confuse
>>>gravity and inertia. Bodies at rest and in motion and all that other
>>>tricky stuff that, it seems, is best left to the simulator programmers.
>>>Gravity has little to do with it (apart from traction).
>>>--
>>>Stephen Ferguson
>>Gravity HAs a lot to do with it, in this case, the gravity of your fuel
>>tank!
>Hold it right there!
>I think you need the difference between inertial mass and weight explained to
you.
>Inertial mass is the degree to which an object can be accelarated by a force.
This
>quantity has got NOTHING AT ALL to do with gravity.
>Weight - the force downwards on an object in a gravitational field - is just
that -
>it is dependant on both the mass AND the magnitude of the gravitational
field.
>The reason cars are slow(in terms of lap times) at the start of the race is
because
>they have a large inertial mass - which means they are harder to make
accelerate.
>If one was racing spaceships in zero gravity, the same phenomenon would
occur:
>lap times (round our space track) would become faster as the spacecraft
>became lighter (in terms of their inertial mass).
>Their weights would remain zero.
>> Mass=slow, that's why your car is slow at the start of a 100% race,
>>and fast at the end (if you didn't***up your tires of course...)
>The same is true when braking. The greater the mass the harder to
Here goes.....
1) Racing tires (tyres?) are not only mechanically stuck on the track, but
chemically, as well. Those little clumps that Indycars leave all
over Lakeshore Blvd. are REALLY STICKY, like chewing gum. Friction is
never independent of mass (or more properly, weight). Slide a book across
a table. Now have Murray Walker sit on it. Which is harder to move??
2) Friction's force is a product of a friction coefficient, cleverly called
'the coefficient of friction', and has two values, static and kinetic.
static is higher, always, and is effective whenever an object is at rest
and a force is trying to move it. Since the velocity of a tire is zero
(at the bottom of the tire, where it touches the ground- else it would
spin, like a burnout), static applies. Since kinetic is less, a spinning
tire is easier to keep spinning than it is to start the thing spinning.
That out of the way, friction is governed by the equation F=uN.
F is frictional force, u is the coefficient (called 'mu') and N is the
normal force (force perpendicular to the plane of motion). Note that
both F and N are vectors, and F is parallel to the plane of motion.
In this case, N is the WEIGHT (not mass) of the object, let's
call it 1/4 of the car's weight for simplicity. Now, 1/4 of the weight will
give F=u*(mass of car/4)*g, where g is gravity. If mass is increased, say
due to Prost having a nosejob OR running with a full fuel load, than the
normal force will be larger by 1/4 of the larger amount, and thus higher
friction will result. Thus (whew!) friction is NEVER independent of weight
(assuming fixed 'g', it's mass dependent also) SO.... the heavier car has
better grip through corners, all other things being equal. It might have a
greater tendency to slide off, even with more frictional adhesion. This
is covered in Chapter 2, Inertia and the Chicane.
3) Using your a=F/m arguement as it applies to friction...here goes...
a=F/m F=uN
a=uN/m (replace F with uN, as the friction eqn. allows)
a=umg/m (replace normal force (N) with m*g, the weight)
a=g (acceleration in this case is gravity)
g=umg/m
1=u (you have now proven that all friction coeff's are =1)!
Obviously incorrect, as I once found out on a dynamics exam.
4) The friction caused by the tires is the maximum limit of force that they
can exert on the track. This is (hopefully) never exceeded (are you
listening, Gerhard?!??), since the tires spin if it is. As far as a heavier
car accelerating slower- the force the car can impart to the track is more or
less constant during a race- so F=ma here, but in a different direction
(accelerating forward) and with the force constant, and a higher
mass (fuel, or maybe Nigel's donut) the acceleration will drop. There
are more issues involving kinetic energy and inertia, but I'll leave that
for another physics student....
Sigh. Time for coffee.
Jeff
Correct, absolutely. But more people think of F1 as the absolute
leading (err, bleeding) edge of racing, so the fans are secondary as far as the
'spectacle' of racing. As it should be with a series that says it is the
pinnacle.
Indycar 1-mile ovals are a blast. Sitting on the straights at Toronto
sucked big-time. Sitting at an 'S' in Montreal, however, was much better.
No way you can't say that ovals are more show than race- particularly
with the equalizer (err, yellow) flags....
