motorcycle weight vs. stopping distance

[jellyrug]

if the g-meter was calibrated to the correct calulation that would cause the box to trip the stick would it happen every single time? why not?

It depends on how accurately the G meter is calibrated. Too fine, it will not trip every time, because of variances which are normal in manufacturing of the container, but most important, because the container will not be dropped and land perfectly flat every time. It means the container will deform and absorb some of the shock differently every time, also the bounce will not be the same every time. Nice case for drawing a normal distribution curve.

 

[MelodicMetalGod]

Depends on whether we have brakes on each single car, and whether all those brakes are 100% effective.

So, tell me, do you think Newton was a nut case and everyone who does not understand his principles are normal????

 

[MelodicMetalGod]

Tangent Alert:

The theory of quantum events occuring as waves has been mentioned. I was just today recalling with an associate the idea of gravity waves but I couldn't recall the flesh of the concept. Robot, jellyrug - any thoughts?

 

[Mr Bogus]

hmm preliminary "experiment" results... the break away point was the same on a couple different identical objects (identical surface contact area) but different weights..

 

[jellyrug]

hmm preliminary "experiment" results... the break away point was the same on a couple different identical objects (identical surface contact area) but different weights..

Biscuit

You are practicing what I call the "Sex" theory. It has been done trillions of times before, but you only know what it's like once you have done it yourself.

 

[Mr Bogus]

does this mean I am gettin laid tonight?

 

[jellyrug]

does this mean I am gettin laid tonight?

Get into the back of the line friend!!

 

[copskahn]

while rider ability is an important factor in stopping a motorcycle effectively,you have to compare apples to apples. if you have identical motorcycles traveling at the same speed, one with a 150lb rider and one with lets say a 300lb rider the one with the 150lb rider will stop in a slightly shorter distance considering both riders are of the same skill level. as the front forks compress the tire patch will increase on the pavement but not to a degree that it would make much difference with the different weights of the riders.

 

[kml]

hmm preliminary "experiment" results... the break away point was the same on a couple different identical objects (identical surface contact area) but different weights..

Is you experiment analogous to a motorcycle with a locked and sliding tire or a rolling tire?
Is there a difference in amount of friction between a sliding object and a static object?

cheers
ken

 

[jellyrug]

Is you experiment analogous to a motorcycle with a locked and sliding tire or a rolling tire?
Is there a difference in amount of friction between a sliding object and a static object?

cheers
ken

I could be a smart ass and tell you that a static object has no friction.

But, I know what you mean. The coefficient of friction between rubber and asphalt is not linear. This means that a warm tire has a higher coefficent of friction than a cold tire. Means it will be more difficult to break traction on a warm tire. Once traction is broken, things change drastically though, as the smoke you see is rubber burning. At this point the rubber is increased to a temperature where the coefficient of friction is greatly reduced. This is why ABS works so well, all you are doing is maintaining traction, preventing smoke, or preventing overheated rubber.

So, in short, once you break traction it becomes a totally different world, as the coeffient of friction is greatly reduced.

The reason we put wider tires on a race car, is because the bigger the contact patch, the less pressure (pressure = force/area) between the rubber and the asphalt, accordingly a heat reduction when traction is broken and the coefficient of friction decreases less, means less skidding. Mainly, less pressure between the rubber and the asphalt, means more laps out of the same tire.

Race drivers try all kinds of tricks in a corner, to get a big rubber patch on the correct wheels to increase traction, but this is due to other forces caused by inertia, which could make the rear end, or front end wash out.

For purposes of predicting stopping distance with different weights, we have to assume maximum braking, just before traction is broken.

Yawn. I use to do this stuff for a living a long time ago, no more posts, flame as much as you wish.

 

[sailortrash]

Does increasing a motorcycle's weight increase the stopping distance for a given speed during a maximum braking event.

A. true

B. false

A simple physics

 

[Charlesbusa]

While increased weight gives you more traction to apply more braking to the motorcycle, I don't think that the increased ability to apply more braking power can overcome the additional momentum. So yes a heavier motorcycle can apply more braking power to the street, but I believe it still takes longer to stop.

I have no facts to support my opinion

 

[Robot]

I could be a smart ass and tell you that a static object has no friction.

But, I know what you mean. The coefficient of friction between rubber and asphalt is not linear. This means that a warm tire has a higher coefficent of friction than a cold tire. Means it will be more difficult to break traction on a warm tire. Once traction is broken, things change drastically though, as the smoke you see is rubber burning. At this point the rubber is increased to a temperature where the coefficient of friction is greatly reduced. This is why ABS works so well, all you are doing is maintaining traction, preventing smoke, or preventing overheated rubber.

So, in short, once you break traction it becomes a totally different world, as the coeffient of friction is greatly reduced.

The reason we put wider tires on a race car, is because the bigger the contact patch, the less pressure (pressure = force/area) between the rubber and the asphalt, accordingly a heat reduction when traction is broken and the coefficient of friction decreases less, means less skidding. Mainly, less pressure between the rubber and the asphalt, means more laps out of the same tire.

Race drivers try all kinds of tricks in a corner, to get a big rubber patch on the correct wheels to increase traction, but this is due to other forces caused by inertia, which could make the rear end, or front end wash out.

For purposes of predicting stopping distance with different weights, we have to assume maximum braking, just before traction is broken.

Yawn. I use to do this stuff for a living a long time ago, no more posts, flame as much as you wish.

WOW! This seems to be the never ending thread

Ill continue to try and throw out some friendly and relevant,(this time), physics.

"I could be a smart ass and tell you that a static object has no friction."

This statement is completely wrong, Mu sub s, is all about static friction. A car sitting at a stoplight has static friction, A car racing down the track has static friction. ONLY when the tire starts slipping on the surface do we go to Kinetic friction.
Friction is still there sitting at the stoplight, you just have no other forces(or pseudo forces opposing it).

"So, in short, once you break traction it becomes a totally different world, as the coeffient of friction is greatly reduced."

This statement is completely correct. This is the whole point of anti-lock brakes and traction control. Once the tire starts to slip you have less friction, hence, less braking or less acceleration.

 

[Robot]

Tangent Alert:

The theory of quantum events occuring as waves has been mentioned. I was just today recalling with an associate the idea of gravity waves but I couldn't recall the flesh of the concept. Robot, jellyrug - any thoughts?

My "understanding" of "Gravity Waves" goes back to Einstein. Space and Time are two threads woven into the same fabric, you can't have one without the other. If you distort one you distort the other.

This "Spacetime fabric" can and is distorted. Any object with mass distorts the fabric. Energy densities(i.e magnetic field in a solenoid) distorts the fabric. Velocity also distorts the fabric. This was submitted by Einstein with both General and Special relativity. This theory has been supported by many experiments.

Imagine standing on a mattress with you feet distorting it, if you dropped marbles they would congregate around your feet. An oversimplified example of a plantet, etc, distorting spacetime.

It seemed reasonable to many,(including Einstein), that sudden changes to things in the fabric, (supervova, etc.) could set up waves in the fabric.

These waves should propegate over large distances and be detectable, as tiny fluctuations in gravity. Many experiments have been set up, no waves detected yet, no ones seem to have a good answer why not.

Gravity DOES fluctuate here on earth. It is (generally) greatest at the surface, (mountains and valleys have influence), and falls off as you go above or below the surface.

There is even a point in the ocean, where there is a slight depression, where the ocean itself goes slightly below sea level. The theory is the earth's mantle in this area is extremely dense. I think it could only be detected from space. I think we are talking feet, NOT tens or hundreds of feet difference.

 

[Robot]

While increased weight gives you more traction to apply more braking to the motorcycle, I don't think that the increased ability to apply more braking power can overcome the additional momentum. So yes a heavier motorcycle can apply more braking power to the street, but I believe it still takes longer to stop.

I have no facts to support my opinion

I agree 100%, (within reasonable motorcycle numbers), My best guess is the added traction (benefit) from added weight is less than 10% of the (detriment) to braking distance

Massive Trains etc. I think, we are looking at some different variables.

 

[Robot]

while rider ability is an important factor in stopping a motorcycle effectively,you have to compare apples to apples. if you have identical motorcycles traveling at the same speed, one with a 150lb rider and one with lets say a 300lb rider the one with the 150lb rider will stop in a slightly shorter distance considering both riders are of the same skill level. as the front forks compress the tire patch will increase on the pavement but not to a degree that it would make much difference with the different weights of the riders.

I agree completely If you got the bike up to over 100mph, that extra 150lbs should make for a stopping distance many feet longer.

 

[jellyrug]

WOW! This seems to be the never ending thread

Ill continue to try and throw out some friendly and relevant,(this time), physics.

"I could be a smart ass and tell you that a static object has no friction."

This statement is completely wrong, Mu sub s, is all about static friction. A car sitting at a stoplight has static friction, A car racing down the track has static friction. ONLY when the tire starts slipping on the surface do we go to Kinetic friction.
Friction is still there sitting at the stoplight, you just have no other forces(or pseudo forces opposing it).

Robot, Robot, Robot....

The origin of the word "friction" comes from Latin, from fricare, which means to rub.

Your normal dictionary has definitions:

1.) The resistance that one surface or object encounters, when moving over another.
2.) The action of one surface or object rubbing against another.
3.) Conflict or disagreement.

So, may I use the third definition to say we "disagree", because when your Busa has an engine which is not running, there is no "friction", because your rings and pistons are not "rubbing" against your cylinders.

I'm just joking with you OK. Yes, the words static and kinetic friction were added later years to our English language and the two coefficients are slightly different, but really it will be more clear to talk about a "static coefficient of friction", than static friction.

"Static Friction" is when my wife is really angry with me and I can see the hate in her eyes, but she does nothing. "Kinetic Friction" is when she starts throwing stuff at me.

 

[Mr Bogus]

cant we talk about the coefficient of friction under the wheel of a 100,000 ton train when they have to dump sand under the wheels?

 

[Robot]

Robot, Robot, Robot....

The origin of the word "friction" comes from Latin, from fricare, which means to rub.

Your normal dictionary has definitions:

1.) The resistance that one surface or object encounters, when moving over another.
2.) The action of one surface or object rubbing against another.
3.) Conflict or disagreement.

So, may I use the third definition to say we "disagree", because when your Busa has an engine which is not running, there is no "friction", because your rings and pistons are not "rubbing" against your cylinders.

I'm just joking with you OK. Yes, the words static and kinetic friction were added later years to our English language and the two coefficients are slightly different, but really it will be more clear to talk about a "static coefficient of friction", than static friction.

"Static Friction" is when my wife is really angry with me and I can see the hate in her eyes, but she does nothing. "Kinetic Friction" is when she starts throwing stuff at me.

It's all goodMy definitions come from Physics Text to define Mu sub s(static friction) and Mu sub k(kinetic friction), these terms are well defined in physics and directly applicable, as to how physics would approach this problem.

Interesting(strangely) enough Mu sub s is the SAME friction for the standing still car as it is for the moving car(as long as the tires arent slipping on the pavement).

It is assumed this contact patch from the moving car is fairly constant and static, even as the tire rotates.

It's all cool:agree: Just a "somantics" issue

 

[Mr Bogus]

It's all goodMy definitions come from Physics Text to define Mu sub s(static friction) and Mu sub k(kinetic friction), these terms are well defined in physics and directly applicable, as to how physics would approach this problem.

Interesting(strangely) enough Mu sub s is the SAME friction for the standing still car as it is for the moving car(as long as the tires arent slipping on the pavement).

It is assumed this contact patch from the moving car is fairly constant and static, even as the tire rotates.

It's all cool:agree: Just a "somantics" issue

and the KML spelling police are on the way too....