Thread: I need help (its sort of science related)

So alright i got pulled over for speeding..or they say...

it was late, and i miss read the sign so i started to go faster, the cop PASSED ME and was in motion, is it possible for a Cop to cite the correct speed if he was comming towards me and we were both in motion?

i just dont see how it can be done im thinking of fighting it and maybe have that as a reason but im not really sure if im right but is that possible? and if it is or isnt can you please explain how so?

Radar

Ah, and his exceeding the speed limit does not entail a lack of ability to determine that he (or anyone else) is exceeding the speed limit. He knows he is exceeding the speed limit, and he's probably good at figuring these things out anyway.

Yes it is possible (I think). Because they measure the distance between them and you. They know what speed they are driving with and this way they can calculate how fast you are driving. Though I don't know if it is possible to do this in such a short amount of time. :?

True but in a 3 second time could they really do all of that? i dont believe it. because the radar is also moving in the car so how can it be acurate, and even so if he did ""figure it out"" i dont think it would go in court as soild proff.

i just dont get how it can be possible to BE moving and trying to get the speed of something that is moving towards you at the same time, he would have to be able to calculate how far away i was, how fast hes going, and figure all of that in and do that in his head in a matter of seconds is that even possible to do?

I would say yes. Radar.

If he is coming at you at 45 mph and you are going 55 in the opposite direction, the radar would say 100 mph. He just simply subtracts his speed and he gets 55 mph, your speed.

Originally Posted by Manmaderomance4

i just dont get how it can be possible to BE moving and trying to get the speed of something that is moving towards you at the same time, he would have to be able to calculate how far away i was, how fast hes going, and figure all of that in and do that in his head in a matter of seconds is that even possible to do?

NO it probably isn't. Even if he wanted to measure your speed he had to know you were coming up. I just think he kind of 'saw' you driving to fastand give you a ticket for that, i can't be sure though. Cops can be strange people sometimes.

Originally Posted by Absane

I would say yes. Radar.

If he is coming at you at 45 mph and you are going 55 in the opposite direction, the radar would say 100 mph. He just simply subtracts his speed and he gets 55 mph, your speed.

are you really sure thats how it works?

i got a 45 in a 35 but he said he cited me at 50 something, but my needle didnt say that much and im pretty sure of it so maybe its off or he made a mistake

Well here are two links I found that might be useful:

http://www.escortradar.com/errors.htm

http://www.magma.ca/~fyst/appndxc.htm

This quote is from the second page:

There is a variation of traffic radar, which is called moving radar. It works pretty much the same way as the type described above (stationary radar), only that moving radar is used when the cop car is moving (for the purpose of highway patrol, for example). There are two readouts on the radar unit, one shows the target speed, one shows the cop car speed. The strongest return signal, usually reflected from highway signs, bridges or other objects, is assumed to be the cop car speed. The next strongest signal, is assumed to be from the target. Since the target speed will only be relative to the cop car speed, therefore by adding the cop car speed to the relative target speed, one will get the absolute speed of the target. Moving radar is subject to all the errors stationary radar has, plus the error of determining the cop car speed.

So it works Is there annything that can't be done with moder technologie? 8)

im pretty happy about what you showed to me, i relized that radars can yes do such in motion, but have errors, so looking into the errors i relized that it could reflect of a near by sign, or even off the mirrors that are in the cops car, and when iwas pulled over, i was within 400m of a very large alcoa plant, that could be why he was getting a large cited, and being i was the only car around, he pulled me over.