EVERYBODY NEEDS TO KNOW!!!

[ElFenix]

when your tires lose contact with the pavement - your car will accelerate to a higher rate of speed

actually thats impossible.

 

[deerslayer]

Thanks for the info.

 

[notfred]

Originally posted by: ElFenix

when your tires lose contact with the pavement - your car will accelerate to a higher rate of speed

actually thats impossible.

Not really impossible, push your car off a cliff and record the speed before and after the tires leave the pavement

But yes, in the case in the story it makes no sense at all.

 

[isekii]

I havne't used Cruise control for like 2 years. Damn assholes cutting in left and right even on an open highway.

I had one asshole cut right in front of me on a 3 lane highway, when there were no cars infront of him or next to him.

 

[PlatinumGold]

Originally posted by: ElFenix

when your tires lose contact with the pavement - your car will accelerate to a higher rate of speed

actually thats impossible.

hmmm, let's see, what are the laws of thermodynamics with regards to objects in motion?

now what would happen to the object if the friction were removed?


yes, it is very possible.

 

[Mutilator]

Lets say you are in a RWD car on a dyno or something... you set the cruise control to 45MPH. You then have someone lift up the rear wheels off the dyno so they no longer have any resistance (like hydroplaning)... I can almost guarantee you that the wheels will spin MUCH faster if only for a brief second... I don't think cruise control can compensate for such a drastic change in speed... I know my Lightning manual says it turns off if it senses a 10MPH change going up or down hill. So if you look at it that way... this makes a lot of sense.

Not that I care... I have a steady foot so I never use cruise control.

 

[ElFenix]

Originally posted by: PlatinumGold

Originally posted by: ElFenix

when your tires lose contact with the pavement - your car will accelerate to a higher rate of speed

actually thats impossible.

hmmm, let's see, what are the laws of thermodynamics with regards to objects in motion?

now what would happen to the object if the friction were removed?


yes, it is very possible.

its not going to gain speed without the tires pushing the cars down the road, so, no, its not. (except notfred's gravity driven example)

 

[ElFenix]

Originally posted by: Mutilator
Lets say you are in a RWD car on a dyno or something... you set the cruise control to 45MPH. You then have someone lift up the rear wheels off the dyno so they no longer have any resistance (like hydroplaning)... I can almost guarantee you that the wheels will spin MUCH faster if only for a brief second... I don't think cruise control can compensate for such a drastic change in speed... I know my Lightning manual says it turns off if it senses a 10MPH change going up or down hill. So if you look at it that way... this makes a lot of sense.

Not that I care... I have a steady foot so I never use cruise control.

and exactly how much faster is the car traveling when you pick it up off the dyno? 0!

 

[pyonir]

Regardless if the car speeds up or slows down, the cruise will still be on. That means the tires won't slow down to get back in contact with the road. The tires will still be hydroplaning because they are not slowing down.

 

[Mutilator]

Originally posted by: ElFenix

Originally posted by: Mutilator
Lets say you are in a RWD car on a dyno or something... you set the cruise control to 45MPH. You then have someone lift up the rear wheels off the dyno so they no longer have any resistance (like hydroplaning)... I can almost guarantee you that the wheels will spin MUCH faster if only for a brief second... I don't think cruise control can compensate for such a drastic change in speed... I know my Lightning manual says it turns off if it senses a 10MPH change going up or down hill. So if you look at it that way... this makes a lot of sense.

Not that I care... I have a steady foot so I never use cruise control.

and exactly how much faster is the car traveling when you pick it up off the dyno? 0!

Someone really should try this...
The way I see it is if you're giving the car 30% gas... say the engine is rotating at 3000RPM in 4th gear. If you lift the wheels up off the ground the engine no longer has anything pushing back against it... so that same 30% push on the gas pedal is going to result in a MUCH faster speed to the wheels. I don't see why that's so hard to understand. Guess you could try it with a pedal bike or motorcycle a little easier than a car though.

Edit: I know for a fact this is how it would work... I remember jumping go-carts and 4 wheelers as a kid... if you were going full throttle and hit a jump and went airborne the wheels would spin much faster. I'm making the connection with the gas pedal because I remember watching the gas pedal in my Dad's old Buick go back and forth when he had cruise on as a kid.

I dunno, maybe it's engine speed, maybe it's wheel speed, maybe it's both.
Might have to move this thread to the Highly Technical forum lol.

 

[pyonir]

Originally posted by: Mutilator

Someone really should try this...
The way I see it is if you're giving the car 30% gas... say the engine is rotating at 3000RPM in 4th gear. If you lift the wheels up off the ground the engine no longer has anything pushing back against it... so that same 30% push on the gas pedal is going to result in a MUCH faster speed to the wheels. I don't see why that's so hard to understand. Guess you could try it with a pedal bike or motorcycle a little easier than a car though.

I thought the CC controlled the speed of the tires, not the amount of pressure on the accelorator.

 

[hdeck]

hmm...interesting...

 

[DorkBoy]

Anyone with common sense would not use CC in the rain or other unsafe driving conditions.
Jeeez

Typical woman driver/idiot :disgust:

 

[N8Magic]

PARTIAL urban legend.

Using CC on a wet or icy road will cause wheel spin (just as if you had your foot on the gas), but it will not cause your car to "take off like a rocket".

For your car to take off like that, you need traction. Where is that traction going to come from when the wheels are spinning?

That being said, wheel spin can cause a skid and/or loss of control so CC should be avoided in slippery conditions.

 

[Brutuskend]

Link one

Link two

 

[PlatinumGold]

Originally posted by: ElFenix

Originally posted by: PlatinumGold

Originally posted by: ElFenix

when your tires lose contact with the pavement - your car will accelerate to a higher rate of speed

actually thats impossible.

hmmm, let's see, what are the laws of thermodynamics with regards to objects in motion?

now what would happen to the object if the friction were removed?


yes, it is very possible.

its not going to gain speed without the tires pushing the cars down the road, so, no, its not. (except notfred's gravity driven example)

Anything in motion tends to stay in motion. it's one of the basic tenets of the laws of thermodynamics.

Let's say you accelerate to a certain speed, say 60 mph. in order to maintain that speed you have to overcome certain things, aerodynamics (amount of pressure from the air) but a much more significant factor is friction of axle, wheels, tires on road, etc.

IF you start hydroplaning you have totally changed the dynamics of that friction. and for a short period of time you will actually accelerate.

IS there a physicist in the house so that you can show this mathematically. i'm just doing it on strict intuition and i know i'm right i just can't do the mathematical proof.

btw, at some point in time (whethor it be 1/10 of a sec or 10 secs) at some point the inertia will be lost and you will start to decelerate, but initially you will accelerate beyond the speed you started at.

 

[jemcam]

and you take off like an airplane...

It all seemed believable until I saw that part.

 

[Mutilator]

Originally posted by: Brutuskend
Link one

Link two

With some cars, it is possible that the wheels will actually spin faster when the cruise control is on and the car hits a slippery spot. When the tires make contact with firm road again, the car can skid or lose control.

Guess that just about sums up what I was trying to say.

 

[pyonir]

Originally posted by: PlatinumGold

Anything in motion tends to stay in motion. it's one of the basic tenets of the laws of thermodynamics.

Let's say you accelerate to a certain speed, say 60 mph. in order to maintain that speed you have to overcome certain things, aerodynamics (amount of pressure from the air) but a much more significant factor is friction of axle, wheels, tires on road, etc.

IF you start hydroplaning you have totally changed the dynamics of that friction. and for a short period of time you will actually accelerate.

IS there a physicist in the house so that you can show this mathematically. i'm just doing it on strict intuition and i know i'm right i just can't do the mathematical proof.

btw, at some point in time (whethor it be 1/10 of a sec or 10 secs) at some point the inertia will be lost and you will start to decelerate, but initially you will accelerate beyond the speed you started at.

But that doesn't matter in this instance because you are hydroplaning. You have no contact with the road and the acceration will do nothing but cause your tires to spin faster. (I suck at physics, so i am going on my intution on this as well).

 

[conjur]

Originally posted by: PlatinumGold

Originally posted by: ElFenix

when your tires lose contact with the pavement - your car will accelerate to a higher rate of speed

actually thats impossible.

hmmm, let's see, what are the laws of thermodynamics with regards to objects in motion?

now what would happen to the object if the friction were removed?


yes, it is very possible.

The car doesn't increase its rate of speed...the tires increase their rate of spinning!

If there's little or no friction, just how the hell is the entire vehicle going to accelerate?

As a test, put your car on a lake of ice and floor it. Tell me what happens.

Yeah....thought so.



And, her car didn't take off like an airplane. It simply slid across a slick surface. I doubt she was traveling fast enough to actually go airborne like some NASCAR accident. Well, if she slid across a ditch or median and the car was launched into the air due to the slope of the ground, sure.

 

[PlatinumGold]

Originally posted by: conjur

Originally posted by: PlatinumGold

Originally posted by: ElFenix

when your tires lose contact with the pavement - your car will accelerate to a higher rate of speed

actually thats impossible.

hmmm, let's see, what are the laws of thermodynamics with regards to objects in motion?

now what would happen to the object if the friction were removed?


yes, it is very possible.

The car doesn't increase its rate of speed...the tires increase their rate of spinning!

If there's little or no friction, just how the hell is the entire vehicle going to accelerate?

As a test, put your car on a lake of ice and floor it. Tell me what happens.

Yeah....thought so.



And, her car didn't take off like an airplane. It simply slid across a slick surface. I doubt she was traveling fast enough to actually go airborne like some NASCAR accident. Well, if she slid across a ditch or median and the car was launched into the air due to the slope of the ground, sure.

WRONG, we are not talking about starting from a standstill but from MOTION.

IN other words, you are traveling at 60 MPH, that means that there is a certain amount of inertia, there is a certain amount of kinetic energy because you are in motion. IF all friction is REMOVED, you will temporarily INCREASE your speed, NOT because of what your tires are doing but because your KINETIC energy is constant but FRICTION has been removed.

 

[PlatinumGold]

Originally posted by: pyonir

Originally posted by: PlatinumGold

Anything in motion tends to stay in motion. it's one of the basic tenets of the laws of thermodynamics.

Let's say you accelerate to a certain speed, say 60 mph. in order to maintain that speed you have to overcome certain things, aerodynamics (amount of pressure from the air) but a much more significant factor is friction of axle, wheels, tires on road, etc.

IF you start hydroplaning you have totally changed the dynamics of that friction. and for a short period of time you will actually accelerate.

IS there a physicist in the house so that you can show this mathematically. i'm just doing it on strict intuition and i know i'm right i just can't do the mathematical proof.

btw, at some point in time (whethor it be 1/10 of a sec or 10 secs) at some point the inertia will be lost and you will start to decelerate, but initially you will accelerate beyond the speed you started at.

read my post above. again, i'm not talking acceleration due to what the tires are doing but due to the fact of the kinetic energy you've got going because you've already gotten to 60 mph (or whatever).


But that doesn't matter in this instance because you are hydroplaning. You have no contact with the road and the acceration will do nothing but cause your tires to spin faster. (I suck at physics, so i am going on my intution on this as well).

 

[TheBoyBlunder]

Roger that, no cruise control when the pavement is wet.

 

[PlatinumGold]

Let me try once more so that everyone understands.

IF you are traveling at 60 MPH in a 3000 lb car, maintaining that speed requires a certain amount of energy. Part of that energy is used to overcome the friction of the tires on the road. IF all friction is removed, the amount of energy required to maintain that speed is DRASTICALLY reduced, BUT because you have already ACHIEVED the speed, Law of thermodynamics says, ANYTHING IN MOTION wants to stay in motion, it is FRICTION that slows it down.

HENCE, constant energy DECREASE in friction = ACCELERATION.

 

[pyonir]

Isn't wind friction?