C32 Looses To M3
08-08-2005, 09:27 AM
#77
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Obsidian E55
All notes have been read and appreciated.
In the last few weeks i have practiced "MY" optimum launch technique and have found that power-braking up to 1200/1300 rpm range was giving me the balance that i required approximatly, just a slight wheelspin,and feathering the throttle on launch for a split second and then stomping it.
Traction of course will be off,tranny in sport mode and 1st gear pre-selected.Will of course let the tranny do the rest.Tyres i have are normal road tyres,they are brand new "under 500 miles" and are dunlop sp sports,not the best but thats what the stealership put on when aquired my 18"s style IV.
Hopefully the weather will be dry and the surface being warmer allowing for better launches, but then again we do live in the uk and the weather is un-predictable, either way will have to find out nearer the time so fingers crossed.
Imho i cant wait for this rematch as hes been boasting a little too much for my liking. Sorry bro if your reading this
In the last few weeks i have practiced "MY" optimum launch technique and have found that power-braking up to 1200/1300 rpm range was giving me the balance that i required approximatly, just a slight wheelspin,and feathering the throttle on launch for a split second and then stomping it.
Traction of course will be off,tranny in sport mode and 1st gear pre-selected.Will of course let the tranny do the rest.Tyres i have are normal road tyres,they are brand new "under 500 miles" and are dunlop sp sports,not the best but thats what the stealership put on when aquired my 18"s style IV.
Hopefully the weather will be dry and the surface being warmer allowing for better launches, but then again we do live in the uk and the weather is un-predictable, either way will have to find out nearer the time so fingers crossed.
Imho i cant wait for this rematch as hes been boasting a little too much for my liking. Sorry bro if your reading this
08-08-2005, 10:34 AM
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540 6spd
Originally Posted by andy_cyp
2nd run, ... traction on, 1500/2000 rpm then we both floor it,
08-09-2005, 11:35 PM
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CLS55 AMG
Missed this response to Erik the BMW troll:
Originally Posted by Erik
And neither have I 
, Impizz.... learn to read.
, Impizz.... learn to read.
Originally Posted by Erik
( and since we all know that the weight is getting less and less important with increasing speed )....
08-10-2005, 01:53 AM
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ALPINA B12 5,7 Coupe #22/57
Originally Posted by Improviz
I can read just fine, loser...here's what you said:
Maybe you should learn to read...what you already wrote, lol....
Maybe you should learn to read...what you already wrote, lol....
In you language, does "LESS" mean the same as "NOT".
Here is what I wrote earlier....
Originally Posted by Erik
So in low speed like the 0-60 sprint the air resistance in of no practical importance, only weight to power ratio ( and gearing, traction...)
but from high speed like 155 mph it is off huge importance and weight are getting a realivly lesser and lessser important factor.
but from high speed like 155 mph it is off huge importance and weight are getting a realivly lesser and lessser important factor.
Here is also a quote that explains this in a way that even Impizz understands.... ( or probably not....)
Originally Posted by wolverine
Interesting discussion indeed. I've got a BS in Physics, MS in Mechanical Engineering, and have been in design for 25 years. I've done some consulting work for some major car companies, so I'll throw my two cents in here. I'm going to neglect a number of things to keep it simple.
A car moving at a certain speed V will be using part of it's horsepower to overcome the drag force of the air, and let’s say the rest is available to accelerate the car. If a 400 HP car uses 40 HP at 50 mph to overcome the drag force, then it has 360 hp available to accelerate the car. The car will accelerate pretty quickly from 50 mph with 360 HP available.
As your speed V increases, the drag force, (given as f = -1/2cpAV**2) increases as the square of the velocity. So at double the speed, say 100 mph, the drag force increases by a factor of 4. At 100 mph, the 400 HP car is using 160 HP to overcome the drag force, and has only 240 HP available to accelerate the car. Acceleration from 100 mph would be good, but less than what it was at 50 mph.
By 150 mph, the drag force would be 9 times as much, or 360 HP would be required just to keep the car moving. That leaves only 40 hp to accelerate the car, which would gain speed very slowly.
Now, let’s say another car has a slightly higher drag, say 10% more. That would mean that at 150 mph, the car would be using 360 + 36 = 396 hp just to maintain the speed. That leaves only 4 hp available to accelerate the car, basically nothing.
Now you can look at your F=ma calculations and see that even if the horsepower numbers are equal, a heavier car with a better drag number can accelerate faster than a lighter car, if the speed is high enough, because the lighter car is using up more of it’s HP to overcome the drag force. A 4000 lb car with 40 HP will out accelerate a 2000 lb car with 4 HP every time!
I’ve left out friction, time vs distance, and a bunch of other things just to keep it simple. Hopefully this gives people a good idea of how drag influences acceleration.
A car moving at a certain speed V will be using part of it's horsepower to overcome the drag force of the air, and let’s say the rest is available to accelerate the car. If a 400 HP car uses 40 HP at 50 mph to overcome the drag force, then it has 360 hp available to accelerate the car. The car will accelerate pretty quickly from 50 mph with 360 HP available.
As your speed V increases, the drag force, (given as f = -1/2cpAV**2) increases as the square of the velocity. So at double the speed, say 100 mph, the drag force increases by a factor of 4. At 100 mph, the 400 HP car is using 160 HP to overcome the drag force, and has only 240 HP available to accelerate the car. Acceleration from 100 mph would be good, but less than what it was at 50 mph.
By 150 mph, the drag force would be 9 times as much, or 360 HP would be required just to keep the car moving. That leaves only 40 hp to accelerate the car, which would gain speed very slowly.
Now, let’s say another car has a slightly higher drag, say 10% more. That would mean that at 150 mph, the car would be using 360 + 36 = 396 hp just to maintain the speed. That leaves only 4 hp available to accelerate the car, basically nothing.
Now you can look at your F=ma calculations and see that even if the horsepower numbers are equal, a heavier car with a better drag number can accelerate faster than a lighter car, if the speed is high enough, because the lighter car is using up more of it’s HP to overcome the drag force. A 4000 lb car with 40 HP will out accelerate a 2000 lb car with 4 HP every time!
I’ve left out friction, time vs distance, and a bunch of other things just to keep it simple. Hopefully this gives people a good idea of how drag influences acceleration.
Last edited by Erik; 08-10-2005 at 02:59 AM.
08-10-2005, 02:27 AM
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CLS55 AMG
In the first place, I never stated that YOU had said weight is NOT a factor. I did point out, correctly, that the author of the post to which you referred clearly DID NOT SUPPORT your argument.
I didn't say you did; I did say that you are wrong in maintaining that mass is less and less important at higher speeds. And I maintain that you are wrong.
Stating that weight is LESS AND LESS (not just "LESS", as you're now trying to rewrite it) of a factor at high speeds is equally false, and shows how utterly ignorant you are about physics.
And you did say "less and less", which implies a linear decrease with speed, not just "less":
OK, so you are stating that as speed increases, mass becomes "less and less" of a factor. Meaning ultimately that as speed approaches infinity, mass has zero effect? Hmm, so let's work this out: force = mass*acceleration. So if acceleration = infinite, then by your reckoning mass is effectively zeroed out, meaning that force =...zero??
Wow. So we can accelerate a body to infinite velocity with zero force!!
So gravity and physics work at 0-60, but no longer work at 100 plus mph? How perfectly idiotic of you.
Can you produce ONE reference to support this bull**** claim that you've repeatedly made, Erik the BMW shill? Because I'm stating that, flat out, you're absolutely, totally wrong in this matter.
Originally Posted by Erik
.........and where excactly in this do I say weight is NOT an factor......
Originally Posted by Erik
In you language, does "LESS" mean the same as "NOT".
And you did say "less and less", which implies a linear decrease with speed, not just "less":
Originally Posted by Erik
and since we all know that the weight is getting less and less important with increasing speed
Hmm, so let's work this out: force = mass*acceleration. So if acceleration = infinite, then by your reckoning mass is effectively zeroed out, meaning that force =...zero?? Wow. So we can accelerate a body to infinite velocity with zero force!!
So gravity and physics work at 0-60, but no longer work at 100 plus mph? How perfectly idiotic of you.
Can you produce ONE reference to support this bull**** claim that you've repeatedly made, Erik the BMW shill? Because I'm stating that, flat out, you're absolutely, totally wrong in this matter.
Last edited by Improviz; 08-10-2005 at 02:59 AM.
08-10-2005, 03:10 AM
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CLS55 AMG
I actually understood wolverine's post perfectly, Erik...
...but you didn't. He simply stated that aerodynamic drag increases with speed, which is true, and illustrated this by way of the equation to describe drag force. Unfortunately, this in no way, shape, or form supports your argument that "mass is less and less important", particularly in a discussion of two cars whose drag coefficients and frontal areas are virtually identical! Why? Well, simple: if drag coefficients and frontal areas are the same, then the vehicles will generate the same (negative) drag force!
I mean, really: this is simple algebra...try to keep up.
The claim you made, originally in this post, was in response to a question about the M5's high-speed acceleration. You wrote:
False. The M5 has more force, but it also has more mass.
And since you understand Physics oh so much greater than I, can you please point out where, in wolverine's post, he ever stated anything which supports your argument that mass is "less and less" important at high speeds, or that at high speeds, "the car with the most hp has more left to accelerate the car", irrespective of its mass?
I further challenge you, again, to produce any physics citation supporting your argument that mass becomes "less and less important" to acceleration at high speeds. Just one.
Why? Well, simple: if drag coefficients and frontal areas are the same, then the vehicles will generate the same (negative) drag force! I mean, really: this is simple algebra...try to keep up.
The claim you made, originally in this post, was in response to a question about the M5's high-speed acceleration. You wrote:
Originally Posted by erik
I`ll try without using a lot of theory.
Since aerodymics on this 2 cars are close to identical, they have to use the same amount of HP to keep the car going, and beating the resisting force of the air , ( and since we all know that the weight is getting less and less important with increasing speed )......... the car with the most Hp has more left to accelerate the car.
Since aerodymics on this 2 cars are close to identical, they have to use the same amount of HP to keep the car going, and beating the resisting force of the air , ( and since we all know that the weight is getting less and less important with increasing speed )......... the car with the most Hp has more left to accelerate the car.
And since you understand Physics oh so much greater than I, can you please point out where, in wolverine's post, he ever stated anything which supports your argument that mass is "less and less" important at high speeds, or that at high speeds, "the car with the most hp has more left to accelerate the car", irrespective of its mass?
I further challenge you, again, to produce any physics citation supporting your argument that mass becomes "less and less important" to acceleration at high speeds. Just one.
Last edited by Improviz; 08-10-2005 at 03:24 AM.
08-10-2005, 05:28 AM
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Originally Posted by Improviz
...but you didn't. He simply stated that aerodynamic drag increases with speed, which is true, and illustrated this by way of the equation to describe drag force. Unfortunately, this in no way, shape, or form supports your argument that "mass is less and less important", particularly in a discussion of two cars whose drag coefficients and frontal areas are virtually identical! Why? Well, simple: if drag coefficients and frontal areas are the same, then the vehicles will generate the same (negative) drag force!
I mean, really: this is simple algebra...try to keep up.
The claim you made, originally in this post, was in response to a question about the M5's high-speed acceleration. You wrote:
False. The M5 has more force, but it also has more mass.
And since you understand Physics oh so much greater than I, can you please point out where, in wolverine's post, he ever stated anything which supports your argument that mass is "less and less" important at high speeds, or that at high speeds, "the car with the most hp has more left to accelerate the car", irrespective of its mass?
I further challenge you, again, to produce any physics citation supporting your argument that mass becomes "less and less important" to acceleration at high speeds. Just one.
Why? Well, simple: if drag coefficients and frontal areas are the same, then the vehicles will generate the same (negative) drag force! I mean, really: this is simple algebra...try to keep up.
The claim you made, originally in this post, was in response to a question about the M5's high-speed acceleration. You wrote:
False. The M5 has more force, but it also has more mass.
And since you understand Physics oh so much greater than I, can you please point out where, in wolverine's post, he ever stated anything which supports your argument that mass is "less and less" important at high speeds, or that at high speeds, "the car with the most hp has more left to accelerate the car", irrespective of its mass?
I further challenge you, again, to produce any physics citation supporting your argument that mass becomes "less and less important" to acceleration at high speeds. Just one.
https://mbworld.org/forums/showpost....4&postcount=44
08-10-2005, 08:02 AM
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ALPINA B12 5,7 Coupe #22/57
Originally Posted by reggid
i made the following post which is what i think is erik is referring to.
https://mbworld.org/forums/showpost....4&postcount=44
https://mbworld.org/forums/showpost....4&postcount=44
I read that one and agree.
, but I was not refering to that one.The problem is that I actually belive ( belived )that Impro is capable of reading like a normal person, and not ONLY to find something he can use to create disagrement. And he is amazing at that.
I have not said or meant that weight is irrelevant.
offcourse is with an important factor.I think most that have read what I have tried to put across have understood that. Impro probably do to, but since he is the person he is he pretend not too.
Maybe he would have understood better if I said " weight is getting relativly less and less important when speed increase" in relation to the total power needed to accelerate a car at high speed.
But anyway what Impro means or think of me is of extremly little importance
Last edited by Erik; 08-10-2005 at 08:14 AM.
08-10-2005, 11:11 AM
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CLS55 AMG
Originally Posted by reggid
i made the following post which is what i think is erik is referring to.
https://mbworld.org/forums/showpost....4&postcount=44
https://mbworld.org/forums/showpost....4&postcount=44
08-10-2005, 11:20 AM
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CLS55 AMG
Erik, hurl insults all you like, but you have not and cannot prove your claim.
You have claimed, repeatedly, that mass is "less and less important at high speeds". I have provided direct quotes from your posts and links to them, and this is irrefutable.
What you haven't done is prove it. There is no reading comprehension issue here: your claim was clear: that mass has "less and less" of an effect upon a vehicle's acceleration at higher speeds. You've made this claim repeatedly, in plain English, and I understand your claim perfectly. I also understand perfectly that it is not true.
I also see that despite my repeated challenges for you to do so, you still have not produced any evidence to support it, and instead are resorting to a time-tested tactic: since you cannot admit that you are wrong, and you have no proof to establish this false claim, you simply shoot the messenger as a diversionary tactic.
Science does not work this way, Erik. Science works this way: if you provide a claim, you provide evidence. Einstein did not establish relativity by proposing it and then insulting any and all who questioned it; he established it by providing proof, which so far you have not, for one reason: you cannot.
Your claim was false, you were wrong, and are too stubborn to admit it. Fine. But taking cheap shots to try and divert attention from your lack of evidence does nothing to establish your claim.
What you haven't done is prove it. There is no reading comprehension issue here: your claim was clear: that mass has "less and less" of an effect upon a vehicle's acceleration at higher speeds. You've made this claim repeatedly, in plain English, and I understand your claim perfectly. I also understand perfectly that it is not true.
I also see that despite my repeated challenges for you to do so, you still have not produced any evidence to support it, and instead are resorting to a time-tested tactic: since you cannot admit that you are wrong, and you have no proof to establish this false claim, you simply shoot the messenger as a diversionary tactic.
Science does not work this way, Erik. Science works this way: if you provide a claim, you provide evidence. Einstein did not establish relativity by proposing it and then insulting any and all who questioned it; he established it by providing proof, which so far you have not, for one reason: you cannot.
Your claim was false, you were wrong, and are too stubborn to admit it. Fine. But taking cheap shots to try and divert attention from your lack of evidence does nothing to establish your claim.
08-10-2005, 12:11 PM
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ALPINA B12 5,7 Coupe #22/57
Originally Posted by Improviz
But taking cheap shots to try and divert attention from your lack of evidence does nothing to establish your claim.
LOL.............. When it comes to insult you are the boss Impro..... you insult every single one that disagree with you. You started the namecalling at me, I just returned the favour.
If you wanted a civil discussion, then you have to start to evaluate your own behavior.
Not everyone dissagering with you are an idiot.
08-10-2005, 12:51 PM
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CLS55 AMG
Gee, what a surprise: more diversions and no evidence.
Still singing the same old diversion song, eh Erik? You have so far produced not a single iota of evidence, not a single shred, nothing. Keep trying to divert, it is most amusing to watch you squirm and wriggle.
08-10-2005, 05:49 PM
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ALPINA B12 5,7 Coupe #22/57
OK, beside the fun of wasting Impros time and enjoying it, it could be interessting with an practical excample to show what I have tried to say.
I let Mr Einstein to do the calculation if he have the time....... :v
But to the rest of you guys...
Take 2 identical cars, Cw app 0.30 ( ex. C-class MB) but different weight and engine power. Gearing is optimized in each car.
Car A 100 Hp and 500 Kg.
Car B 400 Hp and 2000 Kg.
Both cars has 5 Kg/Hp...
Car C 200 Hp and 500 kg.
Car C has 2.5 Kg/Hp
They should then be identical in performance, or ? if NOT doesnt that indicate that the Weight/kg is getting relativly less important as speed increase.
My point and guess is, car B will be faster in topspeed and high speed aceleration.
I would be supprised if car A would get pass 200 kph, while car B probably would hit 300 kph.
Acceleration to 100 kph would maybe be simlular, the time to 200 kph would be quite different...
The interessing thing is, what about car C...... My guess is, car B will outrun it in topspeed and also in the last part of car C speed potential, but neither of the other cars will touch car C in low and midium speed.
If you agree in that, it will mean that I am right in what I have tried to explain.
I let Mr Einstein to do the calculation if he have the time....... :v
But to the rest of you guys...
Take 2 identical cars, Cw app 0.30 ( ex. C-class MB) but different weight and engine power. Gearing is optimized in each car.
Car A 100 Hp and 500 Kg.
Car B 400 Hp and 2000 Kg.
Both cars has 5 Kg/Hp...
Car C 200 Hp and 500 kg.
Car C has 2.5 Kg/Hp
They should then be identical in performance, or ? if NOT doesnt that indicate that the Weight/kg is getting relativly less important as speed increase.
My point and guess is, car B will be faster in topspeed and high speed aceleration.
I would be supprised if car A would get pass 200 kph, while car B probably would hit 300 kph.
Acceleration to 100 kph would maybe be simlular, the time to 200 kph would be quite different...
The interessing thing is, what about car C...... My guess is, car B will outrun it in topspeed and also in the last part of car C speed potential, but neither of the other cars will touch car C in low and midium speed.
If you agree in that, it will mean that I am right in what I have tried to explain.
Last edited by Erik; 08-10-2005 at 06:00 PM.
08-10-2005, 11:36 PM
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CLS55 AMG
Your guess?? Your guess is not proof of anything, Mr. Einswine.
But here's a hint for you....from relativity we know that force = mass*acceleration. Now since you don't understand simple algebra (and I'll demonstrate why I say this momentarily), we can simply divide both sides of the equation by the quantity "acceleration", and come up with this handy formula:
acceleration = force/mass.
So, for your hypothesis to be correct, we should see a change in the acceleration between the two examples you give. Now in your hypothesis, you used two masses, which we'll refer to as m1 and m2, and two corresponding forces for each, f1 and f2, such that:
m1 = 500 kg, f1 = 100 hp (Car A)
m2 = 2000 kg, f2 = 400 hp (Car B).
In other words, you simply multiplied m1 and f1 by 4 to get m2 and f2...a consequence of your not understanding algebra and the consequences of your action....but again, more on that in a moment. You claimed that Car B would have faster acceleration than Car A.
So, let's look at this in the general sense. I'm assuming you're not prepared to dispute Einstein's relativity, and so the f=ma is valid in your little world, yes? Good. So, using the simple algebra that you cannot comprehend, let's solve for a1, the acceleration for m1 and f1, and a2, the acceleration for m2 and f2...
So, a1 = f1/m1
= 100/500
= 0.25
So we should now see an increase in acceleration by your (actually that which you took from reggid without considering its ramifications, as you are wont to do) hypothesis, right?
Well, let's see: a2 = f2/m2
= 400/2000
= 0.25
Huh...I'll be damned...last time I checked, 0.25 = 0.25, which means...why, gosh, the two are equal!! Now why do you suppose that is?
Well, the answer is simple: it just goes to show that you, who just very foolishly painted yourself into a corner and fitted yourself with a dunce cap while trying to insult my intelligence and comprehension, are too dense to understand even simple algebra: x/y = 4x/4y, because the 4's in the numerator and denominator cancel...which one learns on the first day of Algebra class.
How incredibly dense of you, Erik....you are hearby given a resounding "F" in your first Algebra I test.
Thank you for the nice gift, Erik...this was too easy.
But here's a hint for you....from relativity we know that force = mass*acceleration. Now since you don't understand simple algebra (and I'll demonstrate why I say this momentarily), we can simply divide both sides of the equation by the quantity "acceleration", and come up with this handy formula:
acceleration = force/mass.
So, for your hypothesis to be correct, we should see a change in the acceleration between the two examples you give. Now in your hypothesis, you used two masses, which we'll refer to as m1 and m2, and two corresponding forces for each, f1 and f2, such that:
m1 = 500 kg, f1 = 100 hp (Car A)
m2 = 2000 kg, f2 = 400 hp (Car B).
In other words, you simply multiplied m1 and f1 by 4 to get m2 and f2...a consequence of your not understanding algebra and the consequences of your action....but again, more on that in a moment. You claimed that Car B would have faster acceleration than Car A.
So, let's look at this in the general sense. I'm assuming you're not prepared to dispute Einstein's relativity, and so the f=ma is valid in your little world, yes? Good. So, using the simple algebra that you cannot comprehend, let's solve for a1, the acceleration for m1 and f1, and a2, the acceleration for m2 and f2...
So, a1 = f1/m1
= 100/500
= 0.25
So we should now see an increase in acceleration by your (actually that which you took from reggid without considering its ramifications, as you are wont to do) hypothesis, right?
Well, let's see: a2 = f2/m2
= 400/2000
= 0.25
Huh...I'll be damned...last time I checked, 0.25 = 0.25, which means...why, gosh, the two are equal!! Now why do you suppose that is?
Well, the answer is simple: it just goes to show that you, who just very foolishly painted yourself into a corner and fitted yourself with a dunce cap while trying to insult my intelligence and comprehension, are too dense to understand even simple algebra: x/y = 4x/4y, because the 4's in the numerator and denominator cancel...which one learns on the first day of Algebra class.
How incredibly dense of you, Erik....you are hearby given a resounding "F" in your first Algebra I test.
Thank you for the nice gift, Erik...this was too easy.
Last edited by Improviz; 08-10-2005 at 11:40 PM.
08-11-2005, 04:16 AM
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Originally Posted by Improviz
Your guess?? Your guess is not proof of anything, Mr. Einswine.
But here's a hint for you....from relativity we know that force = mass*acceleration. Now since you don't understand simple algebra (and I'll demonstrate why I say this momentarily), we can simply divide both sides of the equation by the quantity "acceleration", and come up with this handy formula:
acceleration = force/mass.
So, for your hypothesis to be correct, we should see a change in the acceleration between the two examples you give. Now in your hypothesis, you used two masses, which we'll refer to as m1 and m2, and two corresponding forces for each, f1 and f2, such that:
m1 = 500 kg, f1 = 100 hp (Car A)
m2 = 2000 kg, f2 = 400 hp (Car B).
In other words, you simply multiplied m1 and f1 by 4 to get m2 and f2...a consequence of your not understanding algebra and the consequences of your action....but again, more on that in a moment. You claimed that Car B would have faster acceleration than Car A.
So, let's look at this in the general sense. I'm assuming you're not prepared to dispute Einstein's relativity, and so the f=ma is valid in your little world, yes? Good. So, using the simple algebra that you cannot comprehend, let's solve for a1, the acceleration for m1 and f1, and a2, the acceleration for m2 and f2...
So, a1 = f1/m1
= 100/500
= 0.25
So we should now see an increase in acceleration by your (actually that which you took from reggid without considering its ramifications, as you are wont to do) hypothesis, right?
Well, let's see: a2 = f2/m2
= 400/2000
= 0.25
Huh...I'll be damned...last time I checked, 0.25 = 0.25, which means...why, gosh, the two are equal!! Now why do you suppose that is?
Well, the answer is simple: it just goes to show that you, who just very foolishly painted yourself into a corner and fitted yourself with a dunce cap while trying to insult my intelligence and comprehension, are too dense to understand even simple algebra: x/y = 4x/4y, because the 4's in the numerator and denominator cancel...which one learns on the first day of Algebra class.
How incredibly dense of you, Erik....you are hearby given a resounding "F" in your first Algebra I test.
Thank you for the nice gift, Erik...this was too easy.
But here's a hint for you....from relativity we know that force = mass*acceleration. Now since you don't understand simple algebra (and I'll demonstrate why I say this momentarily), we can simply divide both sides of the equation by the quantity "acceleration", and come up with this handy formula:
acceleration = force/mass.
So, for your hypothesis to be correct, we should see a change in the acceleration between the two examples you give. Now in your hypothesis, you used two masses, which we'll refer to as m1 and m2, and two corresponding forces for each, f1 and f2, such that:
m1 = 500 kg, f1 = 100 hp (Car A)
m2 = 2000 kg, f2 = 400 hp (Car B).
In other words, you simply multiplied m1 and f1 by 4 to get m2 and f2...a consequence of your not understanding algebra and the consequences of your action....but again, more on that in a moment. You claimed that Car B would have faster acceleration than Car A.
So, let's look at this in the general sense. I'm assuming you're not prepared to dispute Einstein's relativity, and so the f=ma is valid in your little world, yes? Good. So, using the simple algebra that you cannot comprehend, let's solve for a1, the acceleration for m1 and f1, and a2, the acceleration for m2 and f2...
So, a1 = f1/m1
= 100/500
= 0.25
So we should now see an increase in acceleration by your (actually that which you took from reggid without considering its ramifications, as you are wont to do) hypothesis, right?
Well, let's see: a2 = f2/m2
= 400/2000
= 0.25
Huh...I'll be damned...last time I checked, 0.25 = 0.25, which means...why, gosh, the two are equal!! Now why do you suppose that is?
Well, the answer is simple: it just goes to show that you, who just very foolishly painted yourself into a corner and fitted yourself with a dunce cap while trying to insult my intelligence and comprehension, are too dense to understand even simple algebra: x/y = 4x/4y, because the 4's in the numerator and denominator cancel...which one learns on the first day of Algebra class.
How incredibly dense of you, Erik....you are hearby given a resounding "F" in your first Algebra I test.
Thank you for the nice gift, Erik...this was too easy.
you neglected an important matter about drag force which you know is a function of V^2 and this reduces the net force acting on the car.
so subtract the same fd (drag force) from the two f's (f1 and f2) and see the result, ..... it shows that as speed increases the heavier car has more acceleration.
while taking a given car and adding mass actually makes it slower. but if you compare cars with similar hp/weight but different actual hp its likely that the heavier and more powerful car will eventually be faster despite being very close at slower speeds. One can interpret this as weight has less importance as the speed increases but this is only partly true.
There are certain assumptions made:
rotational inertia neglected.
two cars have same drag properties.
rolling resistance (weight dependant) is negligible.
08-11-2005, 04:25 AM
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ALPINA B12 5,7 Coupe #22/57
Originally Posted by Improviz
You claimed that Car B would have faster acceleration than Car A.
"My point and guess is, car B will be faster in topspeed and high speed aceleration.
I would be supprised if car A would get pass 200 kph, while car B probably would hit 300 kph.
Acceleration to 100 kph would maybe be simlular, the time to 200 kph would be quite different..."
So try to be correct.
And F=ma is an old friend, so yes its valid in my little world.
Originally Posted by Improviz
acceleration = force/mass.
So, for your hypothesis to be correct, we should see a change in the acceleration between the two examples you give. Now in your hypothesis, you used two masses, which we'll refer to as m1 and m2, and two corresponding forces for each, f1 and f2, such that:
m1 = 500 kg, f1 = 100 hp (Car A)
m2 = 2000 kg, f2 = 400 hp (Car B).
I
So, a1 = f1/m1
= 100/500
= 0.25
So we should now see an increase in acceleration by your (actually that which you took from reggid without considering its ramifications, as you are wont to do) hypothesis, right?
Well, let's see: a2 = f2/m2
= 400/2000
= 0.25
Huh...I'll be damned...last time I checked, 0.25 = 0.25, which means...why, gosh, the two are equal!! Now why do you suppose that is?
Riiiight!
Originally Posted by Improviz
Thank you for the nice gift, Erik...this was too easy.
I`ll try to keep it simple for you..... it would be embarising for you if my guess was more accurate than you calculations. :p
Last edited by Erik; 08-11-2005 at 04:44 AM.
08-11-2005, 04:56 AM
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ALPINA B12 5,7 Coupe #22/57
Originally Posted by reggid
acceleration is Net
One can interpret this as weight has less importance as the speed increases but this is only partly true.
There are certain assumptions made:
rotational inertia neglected.
two cars have same drag properties.
rolling resistance (weight dependant) is negligible.
One can interpret this as weight has less importance as the speed increases but this is only partly true.
There are certain assumptions made:
rotational inertia neglected.
two cars have same drag properties.
rolling resistance (weight dependant) is negligible.
I know, I made a few assumtions, I used 2 identical C-class bodyshells in my excample.Other than that it seems that you agree with me, at least you understand what I am trying to say.... thanks
It could be interessted to see if you also end in Impros idiot cathegory.....,
08-11-2005, 11:19 AM
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Originally Posted by Erik
I said,
"My point and guess is, car B will be faster in topspeed and high speed aceleration.
I would be supprised if car A would get pass 200 kph, while car B probably would hit 300 kph.
Acceleration to 100 kph would maybe be simlular, the time to 200 kph would be quite different..."
So try to be correct.
And F=ma is an old friend, so yes its valid in my little world.
"My point and guess is, car B will be faster in topspeed and high speed aceleration.
I would be supprised if car A would get pass 200 kph, while car B probably would hit 300 kph.
Acceleration to 100 kph would maybe be simlular, the time to 200 kph would be quite different..."
So try to be correct.
And F=ma is an old friend, so yes its valid in my little world.
And I'm well aware what you've claimed, repeatedly, without a shred of proof, which you say again in this post without a shred of proof. Frankly, "it's true because I say it is" really doesn't do much to establish your credibility nor prove your argument, Erik.
Originally Posted by Erik
So according to your little lecture, car A and B will be ecually fast in low speed, medium speed and highspeed acceleration. and F=ma is the only thing important in this.
Riiiight!
Riiiight!
Oh, but I forgot: in the land of ErikPhysics, one does not need to substantiate a claim...one simply claims something to be true, and if questions, refuses to provide evidence and attacks anyone who questions the claim.
Originally Posted by Erik
The pleasure is all mine.
Originally Posted by Erik
-I`ll try to keep it simple for you..... it would be embarising for you if my guess was more accurate than you calculations. :p
Perhaps you might demonstrate with some actual Physics where my calculations were inaccurate? Again: "they're wrong because I say they're wrong" is not gonna cut it. You state that F=MA is accurate in your world. You provide an example of two vehicles with the same force to mass ratios, the same drag coefficients, the same gearing, right down the line...and then you state without proof that f=ma, Newton's Second Law of Motion does not work IN THIS CASE.
Why? Provide some proof. You're contributing nothing more than hot air to this discussion, as is typical for you in between your regular BMW promotion sessions.
"My guess is this" is not proof, Erik, and your guess is all you've provided. You are claiming that one of the key laws of Physics, which has held for hundreds of years, does not work in this case. So you, Erik, are proving Issac Newton wrong??? Ridiculous.
Last edited by Improviz; 08-11-2005 at 12:34 PM.
08-11-2005, 10:47 PM
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Originally Posted by Improviz
Reg, I have a Masters in EE, and took plenty of Physics in my undergrad work, and really don't appreciate your patronizing attitude. A first-year Physics student knows this, and so do I. But the NET drag force for the two vehicles are the SAME.
If you want to stop throwing rocks and start producing some actual equations to back up your argument which seems to be that Newton's Second Law of Motion is not applicable to automobiles traveling at high speed, it would be nice. Got anything concrete to back up this rather extraordinary claim?
NO, I did NOT neglect it, reg; in Erik's original hypothesis post, he stated quite clearly that the Cd on both cars was the SAME. Therefore, the drag force, which is defined as the product of Cd, frontal Area, air density/2, and velocity^2, will be the SAME for the two hypothetical vehicles at any given speed. And since the calculated acceleration was the SAME, subtracting the SAME force from the SAME calculated acceleration will result in the SAME net acceleration. Or are you seriously trying to argue that they would be different, for the SAME vehicle with the SAME Cd and SAME frontal area???
No, reg, it does not. IF the calculated acceleration for the two vehicles is the SAME, then subtracting the SAME drag force from each number gives the SAME answer. This is rudimentary subtraction.
Perhaps you would care to derive this and show the error in my ways? Because what you have done is to make assertions without providing actual equations to back them up, and it's getting tiresome.
You neglect the rotational inertia. You neglect the inertial resistance, which on a heavier vehicle will be HIGHER. AND you neglect Newton's Second Law, supporting Erik in an argument which any first-year Physics student knows to be false. This is patently ridiculous, and I'm sick of it.
But the bottom line is this, reg: does Newton's Second Law hold, or not? If not, perhaps you should get your work published, becuase there does seem to be a rather unanamous agreement amongst physicists that it does.
Answer the question. Was Newton wrong? The net forces on these vehicles is the SAME. If you believe they are NOT, demonstrate HOW.
If you want to stop throwing rocks and start producing some actual equations to back up your argument which seems to be that Newton's Second Law of Motion is not applicable to automobiles traveling at high speed, it would be nice. Got anything concrete to back up this rather extraordinary claim?
NO, I did NOT neglect it, reg; in Erik's original hypothesis post, he stated quite clearly that the Cd on both cars was the SAME. Therefore, the drag force, which is defined as the product of Cd, frontal Area, air density/2, and velocity^2, will be the SAME for the two hypothetical vehicles at any given speed. And since the calculated acceleration was the SAME, subtracting the SAME force from the SAME calculated acceleration will result in the SAME net acceleration. Or are you seriously trying to argue that they would be different, for the SAME vehicle with the SAME Cd and SAME frontal area???
No, reg, it does not. IF the calculated acceleration for the two vehicles is the SAME, then subtracting the SAME drag force from each number gives the SAME answer. This is rudimentary subtraction.
Perhaps you would care to derive this and show the error in my ways? Because what you have done is to make assertions without providing actual equations to back them up, and it's getting tiresome.
You neglect the rotational inertia. You neglect the inertial resistance, which on a heavier vehicle will be HIGHER. AND you neglect Newton's Second Law, supporting Erik in an argument which any first-year Physics student knows to be false. This is patently ridiculous, and I'm sick of it.
But the bottom line is this, reg: does Newton's Second Law hold, or not? If not, perhaps you should get your work published, becuase there does seem to be a rather unanamous agreement amongst physicists that it does.
Answer the question. Was Newton wrong? The net forces on these vehicles is the SAME. If you believe they are NOT, demonstrate HOW.
my statements are from the stand point of comparing two cars with:
- identical drag properties
- same hp/weight
- but different hp and
- different weight
say Car 1 and Car 2 which have 500hp 4000lbs and 250hp and 2000lbs respectively.
the thrust produced by the 500hp car (F1) is twice as much as the 250hp car (F2) (all things being approx equal) but since it has twice the mass the acceleration is the same if drag is ignored
now include drag which is the same for both cars.
acc 1 = (F1-drag)/M1
acc 2 = (F2-drag)/M2
where F1 = 2 x F2 & M1 = 2 x M2
acc1 > acc2 if drag > 0
acc1 = acc2 if drag = 0
eg say F1 = 10000, F2 =5000, M1 = 4000, M2 = 2000, drag = 1000
acc1 = (10000-1000)/4000 = 2.25
acc2 = (5000-1000)/2000 = 2.00
so car 1 with double the hp amd mass of car 2 accelerates faster as the drag increases. Reason being that the drag is a smaller proportion of the engines thrust, meaning the net force on car 1 is less affected by drag.
08-11-2005, 11:25 PM
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Originally Posted by Improviz
But here's a hint for you....from relativity we know that force = mass*acceleration.
Come on, seriously... I don't take issue with your assessment of the facts and figures and your theories and methodologies. But if you are going to try and blind the poor Scandanavian boy with your knowledge of physics, you really do need to get it right....
f=ma is a Newtonian law of physics, which was some few hundred years before Einstein was even born, let alone when he discovered the theory of relativity!!
Also, in an earlier post, I hope you were making a joke about the gas/brake pedal placement being right/left over here - intimating it was the other way round in right hand driving countries. Because if not, then you better take a quick trip to the UK say and drive a car - sure you drive on the other side, but pedal placement is identical..... Have you ever gone out of Texas??
08-11-2005, 11:35 PM
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CLS55 AMG
Originally Posted by mrankovic
Impro-man
Come on, seriously... I don't take issue with your assessment of the facts and figures and your theories and methodologies. But if you are going to try and blind the poor Scandanavian boy with your knowledge of physics, you really do need to get it right....
f=ma is a Newtonian law of physics, which was some few hundred years before Einstein was even born, let alone when he discovered the theory of relativity!!
Come on, seriously... I don't take issue with your assessment of the facts and figures and your theories and methodologies. But if you are going to try and blind the poor Scandanavian boy with your knowledge of physics, you really do need to get it right....
f=ma is a Newtonian law of physics, which was some few hundred years before Einstein was even born, let alone when he discovered the theory of relativity!!
Originally Posted by mrankovic
Also, in an earlier post, I hope you were making a joke about the gas/brake pedal placement being right/left over here - intimating it was the other way round in right hand driving countries. Because if not, then you better take a quick trip to the UK say and drive a car - sure you drive on the other side, but pedal placement is identical..... Have you ever gone out of Texas??
