Speed kills - just plain physics

[Wardsweb]

A body in motion will tend to remain in motion until acted upon by an equal or greater opposing force. Makes you think...

[Bean]

Ouch!

Is that a Honda? :eek:

[feferic]

I hope not... ouch.

I don't think seatbelts helped in that case.

[adam1991]

Speed doesn't kill....speed DIFFERENTIAL kills. So, the differential in speed between the car and the tree is what mattered.

But then, speed differential between the flow of traffic and the old lady doing 50mph *also* matters. She shouldn't be on the road, because speed differential kills.

[Wardsweb]

So anyone know what this use to be?

[anysia]

:eek: :dunno: :angel: :bawling:

dunno.... that's an interesting predicament......

[Unity1]

Originally posted by adam1991
Speed doesn't kill....speed DIFFERENTIAL kills. So, the differential in speed between the car and the tree is what mattered.

But then, speed differential between the flow of traffic and the old lady doing 50mph *also* matters. She shouldn't be on the road, because speed differential kills.

It's not necessarily always about speed differential either.

Situation #1: Car #1 going 45mph in one direction in a lane of traffic... Car #2 going 45mph in the opposite direction in the next lane. Cat #2 veers into Car #1's lane and both cars collide.

The result? Deadly.

Speed differential? Zero.

Situation #2: Car #1 is going down a country highway at 65-70mph and for whatever reason veers off the road and goes off on to the very steep shoulder. The car flips over multiple times.

The result? Death is not assured, but highly likely.

Speed differential? Irrelevant. There was no collision.

The moral of these situations? Speed can and more often than not does kill.

[Wolffit]

Originally posted by Unity1
It's not necessarily always about speed differential either.

Situation #1: Car #1 going 45mph in one direction in a lane of traffic... Car #2 going 45mph in the opposite direction in the next lane. Cat #2 veers into Car #1's lane and both cars collide.
...
The moral of these situations? Speed can and more often than not does kill. [/B]


But if the speed limit is 45, then neither car was doing anything wrong, speed-wise.... And there may not be a speed differential between the two vehicles in this example, but there certainly is a velocity (speed + direction) differential of appx. 90mph, as the cars are travelling in nearly opposite directions. And anyway the speed differential being referred to was the differential between the vehicle before and after the collission with some other object.


Situation #2: Car #1 is going down a country highway at 65-70mph and for whatever reason veers off the road and goes off on to the very steep shoulder. The car flips over multiple times.

Speed differential? Irrelevant. There was no collision.


Sure there was - the car collided with the guardrail (if there was one) and with the ground.

[Unity1]

Originally posted by Wolffit
But if the speed limit is 45, then neither car was doing anything wrong, speed-wise.... And there may not be a speed differential between the two vehicles in this example, but there certainly is a velocity (speed + direction) differential of appx. 90mph, as the cars are travelling in nearly opposite directions. And anyway the speed differential being referred to was the differential between the vehicle before and after the collission with some other object.

What you're referring to is the vector, which accounts for both speed and direction. The point is that there's more than just the difference in speed involved.

[Wolffit]

Yes, velocity is a vector. :} Speed is the scalar component of the velocity vector. The difference in speed between two vehicles going 45mph in opposite directions is 0. The difference in velocity is 90mph in either direction of travel - the magnitude of which is 90mph. I think most people when referring to the difference in speed between two vehicles are referring to the magnitude of the velocity vector. :-)

I think.

[Pairallel]

Can we get college equivalency credit for reading this thread?

If not, please stop torturing my brain...:bawling:

[anysia]

Yeah, I want some physics credits here!!! :D

[snakehair]

I have to agree the difference in speed of people traveling in the same direction is a large factor in traffic disasters. this is especially true here in Maryland where it is not illegal to drive in any lane (no Keep right law) at any speed as long as it is between the upper and lower posted limits. It plays havoc to have cars going 20 mph faster or slower impeding the flow of traffic. It only causes people to take foolish chances and a lot of right side passing (also legal as long as you don't go off the road surface). Liked it a lot more in New England where the lane discipline was more uniform, and you pretty much knew the left was going faster, the right was going slower. Try someof our Washington area highways for a ride of a lifetime.

[my1staccord]

wow that is a first someone complimenting new england drivers!! Then again I am in the worst part of all of new england, I live in Massachusettes on the Rhode Island border. it seems that no one here drives well. the only place that I have seen that is worse was my two weeks in Italy!!:D

[jogo]

the speed differential is relative, one object to another. In this case 90mph

[snakehair]

I grew up and learned to drive around Boston over 40 years ago. I have driven in numerous places and a couple of other countries. My current experience in NE is mostly on 495 and the Mass Pike (we run to Maine several times a year from D.C area). The lane discipline is still better than the Washington, D.C. area. Many factors from no-one is from here, large influx of driver's from other countries, some of the worst commuting in the USA, Maryland's strange laws concerning lane use all combine to create driving reminiscent of going downtown Boston on the expressway back in the early 60's (back when there was only one tunnel to Logan and no one knew what the "big dig" was). Have to admire Bostonian's knowing how to keep up speed and merge. Down here every third person stops at a merge and no-one pays attention to Stop before right turn or even red lights for the first 15 seconds.

[BenjiBoy650]

Uhhh if you ask me...that's a BMW 318ti hatchback.

[Inspector1]

Ford Escort 94-95??

Hey Ben did BMW have passenger side lock cylinder?

I1:)

[BenjiBoy650]

Believe it did but of course nothing is definite :)

[Inspector1]

Hey Wards,
Are you ever going to tell us what it is?

I1:)

[Inspector1]

BUMP???