Haha, nice way to beat the system. But I doubt the symmetry of those two graphs. Surely, there is no (ordinary) retail car on the planet which can accelerate as fast as it decelerates?
First, we assume a spherical car...
Physicist Uses Math to Beat Traffic Ticket
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Re: Physicist Uses Math to Beat Traffic Ticket
#12A friend of mine beat a speeding ticket once by demonstrating that it was physically impossible for him to have slowed down from the claimed speed and stopped in the location where the officer wrote the ticket.
I once failed to beat a speeding ticket by not noticing that the officer had forgot to introduce the ticket into evidence. I introduced it, the judge said "Really? Are you sure?", I missed the hint, and since a ticket is evidence of speeding in Massachusetts, my case was kinda shot...
Re: Physicist Uses Math to Beat Traffic Ticket
#13Haha, nice way to beat the system. But I doubt the symmetry of those two graphs. Surely, there is no (ordinary) retail car on the planet which can accelerate as fast as it decelerates?
A modern hatchback (VW Golf) with good tires on a perfect road can decelerate at 1g with a pro driver. In tests regular drivers posted between 0.9 - 0.6g in a range of cars from Ferrari to Honda civic.
To do 1g in acceleration you would need to do 0-60 in 2.75s that MIGHT be possible for a $1M supercar (or a bike ;-)
Re: Physicist Uses Math to Beat Traffic Ticket
#14> I want to ask the readership to please find the flaw in the argument. "The officer had special two-week training that qualifies him to estimate angular velocity whichever the fucking way he wants, even with a completely obstructed view." Courtesy of Canadian reality. Plot me a graph to counter that .
Right, so I do not know about California, but in Canada if at stop sign the back of your car did not have a chance to come full way down on suspension, the stop is not considered to be performed properly. His charts assume instantaneous change in acceleration let alone any "settle down" period.
Re: Physicist Uses Math to Beat Traffic Ticket
#15Haha, nice way to beat the system. But I doubt the symmetry of those two graphs. Surely, there is no (ordinary) retail car on the planet which can accelerate as fast as it decelerates?
But then the prosecution would have to bring it's own expert witness...over a traffic ticket.
Re: Physicist Uses Math to Beat Traffic Ticket
#16Yeah, that took some dedication, and because we aren't all as dedicated or physicist here are some practical tips I've learned:
1. When an officer asks how fast you were going, never say anything over the speed limit or that's automatic guilt. Just decline to know or tell. A lot of people say within a +5-10mph range over the speed limit because they think that is "ok", but in fact anything over the speed limit is speeding and is ticket worthy.
2. Look up laws in your area about loopholes. I once had a friend who got pulled over for doing a burn out in his Cobra, the officer was so aggravated he forgot to wear his hat when he got out of his car and the case got dismissed because of it.
3. Always be polite. Always, always, always. Even if they're real jerks, which has never happened to me, always be courteous and make things go as smoothly as possible. If you start being an ass they WILL remember it and will take that into consideration when writing the ticket and/or in front of the judge. You'll have a chance to give your side in court, so don't bother wasting your breath with the officer.
4. I once got out of a reckless driving ticket ($400+, I was young and dumb) because I just happened to know the director of the area highway patrol. It turned out I was in the top 5 worst tickets the highway patrolman had ever given out in his 20+ years of duty. My director friend told him I was a good kid and my parents were going to kill me anyway, so he let me off.
5. And really, the single most best way to not get a ticket, don't break the rules. Of course in this guys case the officer apparently was mistaken, but more times than not that's not the case.
This got large quickly. Just some things I've learned over a few years of driving.
Re: Physicist Uses Math to Beat Traffic Ticket
#17Haha, nice way to beat the system. But I doubt the symmetry of those two graphs. Surely, there is no (ordinary) retail car on the planet which can accelerate as fast as it decelerates?
First comment: "venky said... He claims in his model, 'his car decelerated at - 10 m/s^2 and, instantaneously, accelerated to + 10 m/s^2 at t = 0'. No known mechanical system is capable of achieving such an instantaneous jump without a tail-off period. ...."
MechE here, electrical motors can obtain almost instantaneous acceleration / full torque at 0rpm. Their torque curves typically look like this:
http://www.jmag-international.com/catalog/img/e68-3b.gif
The brakes are independent, so it's not as if one system has to provide both accelerations, one just needs exceptional timing of the feet. A lot of rally car drivers can do similar maneuvers
This is the same reason why the Tesla Roadster has such a killer 0-40mph
Re: Physicist Uses Math to Beat Traffic Ticket
#18Haha, nice way to beat the system. But I doubt the symmetry of those two graphs. Surely, there is no (ordinary) retail car on the planet which can accelerate as fast as it decelerates?
MechE here, the limiting factor for car accelerations is usually the static coefficient of friction between the car tires and the road, _not_ the power of the brakes or strength of the engine.
Without ABS braking, it is quite easy to "skid" while applying a harsh brake because you overcome the limit of force between the tires and the road. Similarly, it is quite easy to "burnout" as well with a strong engine for the same reason.
So although the strength of the two systems is not the same, the limiting factor for both of them is identical. Hence, symmetry.
Re: Physicist Uses Math to Beat Traffic Ticket
#19Haha, nice way to beat the system. But I doubt the symmetry of those two graphs. Surely, there is no (ordinary) retail car on the planet which can accelerate as fast as it decelerates?
MechE here, the limiting factor for car accelerations is usually the static coefficient of friction between the car tires and the road, _not_ the power of the brakes or strength of the engine. Without ABS braking, it is quite easy to "skid" while applying a harsh brake because you overcome the limit of force between the tires and the road. Similarly, it is quite easy to "burnout" as well with a strong engine for the…
Car owner here. I don't think this is right.
Re: Physicist Uses Math to Beat Traffic Ticket
#20Earlier quoted context omitted.
MechE here, the limiting factor for car accelerations is usually the static coefficient of friction between the car tires and the road, _not_ the power of the brakes or strength of the engine. Without ABS braking, it is quite easy to "skid" while applying a harsh brake because you overcome the limit of force between the tires and the road. Similarly, it is quite easy to "burnout" as well with a strong engine for the…
Car owner here. I don't think this is right.
Yeah, this argument would only apply to all-wheel-drive cars that are powerful enough to burnout on all four wheels.