>===== Original Message From "George Schiro" <gschiro@lni.net> =====
>I suspect this JATO story is an urban legend as well. However, regarding
>the melted brakes, it isn't the weight of the car that matters but the
>momentum. Momentum goes up with the square of the velocity.
====================================================
Well, you're close. Momentum is the product of mass and velocity, where mass
is the weight divided by gravitational acceleration, 32 ft/sec^2. What you
really meant was Kinetic energy, which is of course (1/2)*mass*velocity^2.
How much it would take to "melt" brakes would take some thermodynamic research
on my part and most of the needed parameters would be specific to the car.
This tale was one of the first "Darwin" awards (given usually posthumously to
a person whose manner of death indicated that the human gene pool was improved
by his/her passing) ever published.
=====================================================
If a mass of
>around 3000 pounds has been accelerated to around 300 mph, trying to
>convert that much kinetic energy into heat, which is what the brakes do,
>would definitely melt a few pounds of cast iron long before the car been
>slowed down by very much.
>
>George Schiro
>
>
>----------
>> From: Phil Martin <pmartin_vacation@hotmail.com>
>> To: htc@MNSi.Net; Bricklin@autox.team.net
>> Subject: Re: How not to go fast
>> Date: Thursday, December 28, 2000 11:37 AM
>>
>> >From: "High Tech Coatings" <htc@MNSi.Net>
>> >Reply-To: "High Tech Coatings" <htc@MNSi.Net>
>> >To: "bricklin" <Bricklin@autox.team.net>
>> >Subject: How not to go fast
>> >Date: Thu, 28 Dec 2000 06:12:59 -0500
>>
>> >Please note: This is a true story except the car was actually a 67
>Impala
>> >(as I received this message), but a the addition of the Bricklin makes
>for
>> >a better story.
>>
>> You might want to look around for some more info on this urban legend.
>This
>> page was interesting:
>>
>> http://www.cardhouse.com/rocketcar/ROCKIT.HTML
>>
>> Although it could easily be bogus too. :)
>>
>> One thing I've been trying to find out for years is just how much thrust
>can
>> a JATO make? If you're talking about a full-sized car like an Impala,
>then
>> we're looking at something like 3500lbs. Most cars can brake at close to
>1g
>> (really rough numbers here), and I have a hard time imagining a single
>JATO
>> making more than say 3000lbs of thrust, so the brakes should be capable
>of
>> stopping it. In any case, you damn sure wouldn't melt the brakes -
>they'd
>> fade and become ineffective long before they had a chance to melt, I'm
>sure.
>>
>> Anyhow, hope this email doesn't sound cantankerous. It is a good and
>> interesting story, and I've been curious about the related physics for
>quite
>> a while...
>>
>> Bye,
>> --
>> Phil Martin
>> "It ain't no sin to be glad you're alive"
>> _________________________________________________________________________
I am Pentium of Borg, Precision is Futile, you will be approximated...
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