I think you're confusing theory and practice. Brakes can overheat, slip, or otherwise fail under enough stress.
I once saw a freight train derail. It was amazing how far the fairly slow moving train moved while off the tracks and wheels sliding along the rock train bed. Momentum is a serious force.
Their point is that tire friction on pavement is not a constant. The more mass, the more force pressing the tires to the pavement and the more friction. The increased friction decreases the stopping distance, while the increased mass lengthens it. No question the effect is there, the only part I'm skeptical about is that one closely cancels out the other. I'd like to see some real world test results.
I recall from freshman physics that the mass normal to the friction surface and cancels out the kinetic energy. Of course, they professor also said the coefficient of friction couldn't exceed 1.0. A new explanation was needed when the fuelie dragsters started posting E.T.'s and terminal speeds that didn't compute.
Generally a Prius that somehow overlooks a 65' long, 13' high 78,000 vehicle with a bright red paintjob and pulls out in front of you. There's also the BMW Z3 piloted by a Master of the Universe that really thinks he's going to win a game of chicken with a Volvo White.
I think the issue here is that the physics are based on certain assumptions and we don't know how well that conforms to what happens with a truck in the real world. The friction force is what's key. We know that the energy of the truck goes up proportional to the mass. The physics of the friction says that it too goes up proportional to the mass, but there must be some set of assumptions along with that. The question is how closely the truck tires fit those assumptions. What works for friction of a piece of sandpaper going across concrete with a 5lb or 10lb weight could be different than what happens with a hot truck tire.
The driver trainer at the company I worked for explained that the company policy forbade firearms in the trucks but common sense suggested a 9mm close at hand was a good idea. A couple of times I had to go to Canada and left my firearm with the terminal manager. Nothing was said.
I imagine ABS has improved a lot, but a bobtail had all the stopping power of a skateboard. Mostly the drivers were rolling or they were locked up unless you were very gentle.
Bullshit.
From: richard Newsgroups: misc.transport.trucking Subject: trailer side skirting ??? Date: Sun, 3 Oct 2010 14:58:03 -0700 Message-ID:
"What's up with trailers having plastic or canvas skirting between the wheels? I've been seeing more and more of them with it."
Maybe because you don't pay attention?
No, others clarified.
ROTFLOL.. How's that dome home coming?
I take it youve never been to Pisa.
A tiny car - AKA a "pisscutter" Likely both rather regional in use. In brittish slang "pisscutter" denotes "not up to much"
From urbandictionary.com: "puddle jumper
A small airplane or land vehicle (car, truck) that appears to be wholly inadequate for the task of transporting passengers, or even the driver for that matter.
Mike: You drove all the way from Minnesota in this puddle jumper? You're braver than I thought."
On 07/12/2014 7:38 AM, trader_4 wrote: ...
...
The above approximate model presumes normal static friction force which is proportional to normal force (weight). Since momentum/energy are proportional to m also, they cancel under that assumption.
The problem is,
"In theory there is no difference between theory and practice. In practice there is." -- Jan L. A. van de Snepscheut
It's an extremely limited theory for a very complex problem.
As for research there's actually quite a lot -- one of the more interesting pieces I saw is at
Hi, Those needs different calculations. Driver said speed was too high meaning he was going over the speed limit? From there accident happened. That is criminal. Also did he check the brakes B4 heading down the hill? That is a requirement for big trucks.
Hi, Also no runaway lane there? He should use it if there was one.
Hi, Heavier mass accelrates more increasing speed.
There was no Italian car industry in Galileo's time. Fiat didn't begin manufacturing until at least a decade of his death. So the Italians had to import all their cars from Germany. That's why Galileo dropped a VW.
Silly mistake. I'll bet your face is red.
Air resistance wouldn't have been a factor.
I own a villa near there.
Oh, gosh. I am so embarassed. I might not be able to post again, for hours.
Not in California. It's against the vehicle code.
Could you cite the section of the California Vehicle Code that mandates this?
Don't kid a kidder. You can't even spell "embarrassed."
Don't wait for hundreds of minutes. Get right back up on that horse.
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