Got caught at 150, cop put 110++ need help with the mnath HELPPPP

  • #1

Main Question or Discussion Point

I need to know what distance a crown vic police car covers from 0-110mph
It was a CHP in san diego and i'm pretty sure they drive the crown vic???
Help
 

Answers and Replies

  • #2
fss
1,179
0
You cannot answer this question without knowing how long it took to reach 110 mph.
 
  • #3
2,685
20
You got caught, suck it up and take the punishment.

Regardless, surely it's irrelevant. If you were still accelerating away from them once they hit 110, you were clearly going faster than them. All the math in the world won't help you.
 
  • #4
Pengwuino
Gold Member
4,989
15
What the hell were you doing going 150mph??
 
  • #5
2,685
20
What the hell were you doing going 150mph??
Trying to get away from a cop car...... :wink:

I love how people try to worm their way out of it when they get caught.
 
  • #6
K^2
Science Advisor
2,469
28
Just for fun of it, lets see. Police Crown Victoria tops out at about 130 mph. Lets assume that at that speed power dissipated to drag equals power delivered by engine. Lets also assume that drag is purely quadratic in speed and that engine always operates at peak power during the 0-110mph acceleration. Yes, I know, that last one is going to make it a bit off, but without going into actual gear ratios of the cruiser, which I can't be bothered to look up, that's the best we can do.

So all in all, very rough estimate, but there is some physics in it.

Engine power: P = 250HP = 186kW
Vehicle mass: m=1700 kg.
Top speed: 130mph = 58m/s
Target speed: 110mph = 49m/s

Power dissipated to drag is given by kv³, and we know it to be equal to engine power at top speed.

Power coefficient: k = 0.953 kg/m.

At any given speed, the force is given by available power over speed.

F = (P - kv³)/v

Hence, the acceleration:

a = P/(mv) - kv²/m

The analytic solution to this equation is so ugly that I want nothing to do with it. On the plus side, numerical solution is easy.

I'm getting 545m traveled in 15s by the time it hits 110mph. That's almost exactly 1/3rd of a mile. Though, 15s is just a touch too fast for 0-110mph. It should take closer to 20s. So the actual number will be a bit higher. Maybe 1/2 of a mile or so.

Regardless, surely it's irrelevant. If you were still accelerating away from them once they hit 110, you were clearly going faster than them. All the math in the world won't help you.
I think he's hoping that they'd knock off 10mph or so if he can "prove" that the cop car couldn't get to 110. Difference in fines at 100 and 110 tends to be significant. (I don't know exact rates in Cali.) Problem is, he's likely to dig himself in deeper if he tries to defend. If it's just a fine, he should go with no-contest, pay the fine, and be glad that's all it cost him. I have a feeling that if the cops actually show up at the hearing, this guy won't be keeping his license.
 
Last edited:
  • #7
2,544
2
im just curious why were you going 150 .
 
  • #8
Ranger Mike
Science Advisor
Gold Member
2,132
201
yeah I drag raced , like everyone else during that period of time...but...we always reconned the road one pass before we lit the tires. checking for the LAW ( obviously you did not - strike one)
we always picked a desolate deserted strip with no access by farm tractors or small children ( you probably did not and chose to randomly speed - strike two)
we were prepared to WALK if we got snagged by the local fuzz and realized driving was a privilege and not a right, so if we got popped don't cry...( strike three)
we made sure the TIRES and steering, suspension were in excellent shape so as not to endanger us or each other ( i doubt you did - strike 4)
we knew the dangers of front end float once you passed 120 mph ( we knew the limits of our vehicle and where the red zone was- again, i doubt you know this)
YOUR OUT- out of luck, out of a car and out for a long time walking
 
  • #9
2,017
85
Can we ban the OP for being an idiot?
 
  • #10
Hey YOU ROCK! Im trying to prove the 1/10 of a second difference between 110 and below 100 is to short at 3/4 mile to visually judge accuratly. i needed the 3/4 mile dist math your 1/2 and I was slightly over the speed limit, :) Fingers crossed

Again THANKS

Just for fun of it, lets see. Police Crown Victoria tops out at about 130 mph. Lets assume that at that speed power dissipated to drag equals power delivered by engine. Lets also assume that drag is purely quadratic in speed and that engine always operates at peak power during the 0-110mph acceleration. Yes, I know, that last one is going to make it a bit off, but without going into actual gear ratios of the cruiser, which I can't be bothered to look up, that's the best we can do.

So all in all, very rough estimate, but there is some physics in it.

Engine power: P = 250HP = 186kW
Vehicle mass: m=1700 kg.
Top speed: 130mph = 58m/s
Target speed: 110mph = 49m/s

Power dissipated to drag is given by kv³, and we know it to be equal to engine power at top speed.

Power coefficient: k = 0.953 kg/m.

At any given speed, the force is given by available power over speed.

F = (P - kv³)/v

Hence, the acceleration:

a = P/(mv) - kv²/m

The analytic solution to this equation is so ugly that I want nothing to do with it. On the plus side, numerical solution is easy.

I'm getting 545m traveled in 15s by the time it hits 110mph. That's almost exactly 1/3rd of a mile. Though, 15s is just a touch too fast for 0-110mph. It should take closer to 20s. So the actual number will be a bit higher. Maybe 1/2 of a mile or so.


I think he's hoping that they'd knock off 10mph or so if he can "prove" that the cop car couldn't get to 110. Difference in fines at 100 and 110 tends to be significant. (I don't know exact rates in Cali.) Problem is, he's likely to dig himself in deeper if he tries to defend. If it's just a fine, he should go with no-contest, pay the fine, and be glad that's all it cost him. I have a feeling that if the cops actually show up at the hearing, this guy won't be keeping his license.
 
  • #11
WAAAA waaaa waaa
Im a corporate pilot for my profession I work on my car and doubt you have the formal training to preflight your car the way i do mine. You never draged if you didnt get above 150unless it was in your bug. In comparison to my skill in the high speed realm that makes you very unsafe and you shouldnt drive over the limit.
Good thing opinions of mighter than thou ness are just those and just like A__holes everyone has one

Cheers

yeah I drag raced , like everyone else during that period of time...but...we always reconned the road one pass before we lit the tires. checking for the LAW ( obviously you did not - strike one)
we always picked a desolate deserted strip with no access by farm tractors or small children ( you probably did not and chose to randomly speed - strike two)
we were prepared to WALK if we got snagged by the local fuzz and realized driving was a privilege and not a right, so if we got popped don't cry...( strike three)
we made sure the TIRES and steering, suspension were in excellent shape so as not to endanger us or each other ( i doubt you did - strike 4)
we knew the dangers of front end float once you passed 120 mph ( we knew the limits of our vehicle and where the red zone was- again, i doubt you know this)
YOUR OUT- out of luck, out of a car and out for a long time walking
 
  • #12
You got caught, suck it up and take the punishment.

Regardless, surely it's irrelevant. If you were still accelerating away from them once they hit 110, you were clearly going faster than them. All the math in the world won't help you.
"Never submit and show your soft underbelly" -Me, 2011

"only dogs lay down and submit" -Me, 2011

"Math" Math"- Me-2011
 
  • #13
2,544
2
when you were drag racing did you win ?
 
  • #14
2,685
20
If a cop car gets to 110mph and you are still getting away then you are going faster than them. There's really not much more to it.

Ooh you're a pilot, big wow. Being a pilot does not make you something special when it comes to driving. Heck, I know pilots who don't know the first thing about cars. So let's stop making utter BS remarks about your "skill in the high speed domain".

You've admitted you were caught at 150mph. Suck it and accept it.

Don't get sh*tty with people here. You come here, asking for us to help you get out of breaking the law and expect people to just accept it? And you follow it up by showing just how poor your attitude is.
"only dogs lay down and submit" -Me, 2011
Tell the cop that next time you're caught at 150 and he pulls his piece on you.
"Math" Math"- Me-2011
Then I suggest you learn it.
 
  • #15
Pengwuino
Gold Member
4,989
15
What kinda person quotes himself?
 
  • #16
2,685
20
What kinda person quotes himself?
I'm thinking of someone with a Kim Jon-Il style attitude about themselves.
 
  • #17
2,017
85
Calling a public vote for ban.

Also OP it's not becuase you drove fast, it's because you failed enough to get caught doing it. Making you a moron.
 
  • #18
2,685
20

Related Threads on Got caught at 150, cop put 110++ need help with the mnath HELPPPP

Replies
22
Views
6K
Replies
3
Views
790
  • Last Post
Replies
19
Views
1K
Replies
35
Views
3K
  • Last Post
Replies
9
Views
837
  • Last Post
Replies
3
Views
9K
  • Last Post
Replies
9
Views
3K
Replies
1
Views
1K
Replies
5
Views
3K
Replies
9
Views
2K
Top