Ticket for no seat belt..... health insurance goes up

Well on an episode of Mythbusters Jamie said two cars hitting at 50 mph was like one car hitting a wall at 100 mph.

Lots of people complained so they did some myth busting, impacting two cars together at 50 mph, impacting one car against a wall at 100 mph, and one car against a wall at 50 mph.

In the two car impact the damage was a lot closer to the car to wall 50 mph impact than the 100 mph wall impact. The video was Jamie talking about what it’s like to have his own myth busted.

In short 40 mph double impact = 40 mph wall impact.

Yes, but we know a car isn’t a wall. Two cars at 40mph each hitting each other is the same as one car at 80mph hitting a stationary car.

No, it isn’t.

Yes, it is. My cite is physics.

ETA If I’m wrong here, an explanation would help, not just a snarky comment.

My cite is Mythbusters rammed two cars together to test it out. Your physics=FAIL.

If car A is going at 40 mph towards car B(also traveling at 40 mph), and car A supposedly hits with an 80 mph force, then it stands to reason that car B also hits with an 80 mph force, right?
Where did all the extra energy come from?

Do you agree that 2 cars of the same weight stop dead after impact, head on, at 40mph each? They have equal momentum(mass*velocity).

impulse=(massvelocity before impact)-(massvelocity after impact)

Car vs car
impulse=(3000x40)-(3000*0)
impulse=120000

Car vs stationary car
impulse=(3000x40)-(3000*0)
impulse=120000

I’ve been wrong about things before, and i’m sure i will be again. Having just done some research of my own, i see that i was, in fact, wrong on this occasion.

But the way to correct someone on something like this is not simply to provide an unexplained link to a video. That is lazy, jerkish behavior. I’m not going to watch a film, just because you can’t be bothered, or don’t understand enough, to give an explanation.

ExcitedIdiot, your math assumed that the stationary vehicle is, like a rock wall, so solid as to completely stop the moving vehicle in its tracks. But it’s not. If you drive into a stationary vehicle at 40 mph, the crash will transfer considerable energy from the moving vehicle to the stationary vehicle, causing the stationary vehicle to move. As a result, the total impact of the crash would be less than two cars coming together at 40 mph each.

As this page notes:

So, it seems that the order of severity goes like this:

=1. Car traveling at 40 mph runs into solid wall.

=1. Car traveling at 40 mph runs head on into another car traveling at 40 mph.

  1. Car traveling at 40 mph runs into stationary car.

After the 80mph car hits the stationary car, both cars would be moving (in the same direction), at roughly 40mph each. The roughly comes because some energy would be lost in the collision.

This may be the difference that Czarcasm is thinking of, but the forces acting on each car at the moment of collision will be the same in both situations.

If for whatever reason the stationary car cannot move freely, the situation will of course be different, but that should be obvious.

“Underwriter” is the term we need here.

Any risky behavior should be fair game for rate increase regardless
of how “minor” and “observable” it is, not that poor driving habits are
in any sense “minor”.

No connection is being made with smoking, drinking, whoring, and sniffing glue.
The connection is between seatbelt use and liklihood of suffering injury requiring
medical treatment.

And BTW, you seem to be saying that smoking and other “private” forms of behavior
and not taken into account in the application process. They are. Some smokers may
get away with lying about it, but most are samrt enough to realize that medical providers
will usually be able to tell if a patient smokes, and that being caught in a lie is ground
for denying coverage.

You’re correct, my second example is wrong. Two cars colliding at 40mph is not equal to two colliding, one at 40mph and one at a standstill.

I still stand by my original point:

Two cars colliding at 40mph is not equal to one car going 80mph into a stationary car.

And it is equivalent to a car traveling at 160mph rear-ending a car traveling at 80mph.

Subtractive velocities

Why should I give a F*** about head on collisions.

Meflin

Thanks for that brilliant and insightful contribution. It’s probably good that you’ve only posted 73 times in your 10 years of membership.

I’m still trying to picture the OP fumbling with his seatbelt as he turns onto a high speed road. Does he then unbuckle again later?

What if the two cars are on a treadmill? Huh??

It’s funny how one’s point of reference changes things. If we were to see a video of an Olympic runner running full-tilt into a wall, we’d expect him to be pretty seriously injured. It hurts just to think about it. But that same speed in a car seems so unbearably slow that it’s hard to take it seriously.

Who pissed in your Wheaties? I gave an explanation to Rhythmdvl when requested. It’s not my fault you traumatized by a pack of wild Mythbuster clips as a child.

No-one did. It’s just a douche move to come into a thread and do nothing but link to a video clip.

It has nothing to do with Mythbusters. I would have said the same thing no matter where the movie was from.