>>You mean you want them to go off before the accident?<<
no, but in this day and age of technology in the event of a crash, I think it should be possible to ensure that the empty space between existing style of airbag and rapidly accelerating body is filled with faster/larger inflated airbag - Mars lander style maybe?
billy
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The advert with the car smoking to a halt, with it's rear wheels merrily turning, was also misleading. It's a Government thing, they think that with most people having gone through the modern 'education' system they'll be too stupid to spot these mistakes, or too frightened of the disapproval of others to voice an alternative point of view.
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I agree with the original poster on this. Unless Number Cruncher cares to set me straight, I see no difference with regard to the internal organs maintaining their momentum regardless of whether the body is stopped by a seatbelt or the steering wheel.
Obviously, far more serious injuries occur in the latter case, but only because the deceleration is that much greater. I appreciate the message that the advert is trying to get across, but it's completely wrong (IMHO!) and should probably be pulled.
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I am glad someone else has spotted this mistake - and I do say mistake.
The deceleration of the body in an accident is determined by the distance over which the body's speed reduces to zero. A shorter distance the greater the force and more likely the internal injury depicted in the advert. Yes, seat belts save lives, but not for the reason stated; they stop people being thrown out of a car or hitting a solid lump of metal or the windscreen. There is no way you can stop the sort of injury depicted by a seatbelt - in fact it will may it worse by reducing the distance in which the body comes to a stop and increasing the force on it.
There is no magic formula to saving lives in a car. Seatbelts work under some circumstances and may well cause greater harm in others, but percentagewise, you are clearly safer wearing a belt. Airbags can also cause some bodily harm, but again overall you are better having an airbag than not.
The best method is to have a jolly great spike sticking out of the wheel pointing directly at your heart. You'll drive a lot more carefully then!!
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In a front end collision the car's deceleration is attenuated by the action of the crumple zone. A body restrained by a properly fitted seatbelt also benefits from this attenuated deceleration. If no seat belt is worn the body decelerates much more rapidly on hitting the steering wheel which, due to the delay in the body reaching it, has come to rest.
The above obviously relates to car with no airbag or where the bag does not deploy. I don't know enough about the forces involved in a body hitting an airbag to understand that scenario.
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Doctorchris - I think you have the correct answer and that the advert is also correct.
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I'd rather be wearing the seatbelt too. The ad is very well done IMO.
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Bill Payer, the Aorta (main artery) detaches from the heart. In practice the effect can be worse than a ruptured heart, ie loss of most of the circulating volume into the chest cavity, no blood to the brain, death. A ruptured heart might just result in a build up of blood around the heart within the pericardium. This situation would give time to get to hospital and receive treatment.
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the advrt is more or less correct although could have been done better.
Scenario A - In an ideal world the body is slowed down gradually by a combination of the seatbelt (which gives slightly as the body comes into contact with it), the SRS airbag also inflates and helps stop the head flailing everywhere. The net effect is that the person is brought to a relatively gradual halt compared with option B.
Scenario B - The person doesn't wear a seatbelt and as the car comes to a halt they continue forwards unrestrained, the SRS airbag deflates as the person hits it and they come to a crushing and immediate halt against the steering wheel or the windscreen pillar.
Points to bear in mind:-
There is no way to prevent momentum building up, the very fact that the person was travelling in the car means that they, and every organ in their body, already have momentum. Even if you managed to hold them still against the seat during the impact the organs would retain their momentum and would continue on to hit the ribcage with some considerable force.
Airbags in the US are different from the EU, over here they are designed to work in conjunction with a seatbelt (hence they are SRS), in the states they are much bigger and designed to act as a restraint in themselves for the whole body.
I'm no physcist so I'm sure that NC will give the full technical jargon soon.
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It's quite amazing how much deceleration the human body can stand. IIRC when an F1 car hit the tyres at Blanchimont a few years ago; it was reported that it went from 184mph to rest in 4 feet and the driver survived 83G.
Edited by Screwloose on 13/11/2008 at 19:37
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>>in the event of a crash, I think it should be possible to ensure that the empty space between existing style of airbag and rapidly accelerating body is filled with faster/larger inflated airbag
Airbags already inflate so fast burns/acoustic injuries can occur, faster inflation would make this worse. Do you want to exacerbate these injuries?
To do what you're suggesting, would require a very fast trigger and, I would suggest, inflation of air bags in situations that don't require them.
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The advert is correct and well done. Seat belts are designed to stretch a little, and so the body decelerates at a steady rate and the internal organs maintain (more or less!) their correct position. Deceleration is limited to about 20g.
Without a seatbelt the body suffers an 'impulse' as it hits the steering wheel and so far more damage is caused - acceleration up to 100g.
I think airbags inflate in just a couple of milliseconds so they are inflated by the time the body has moved forward a short distance and keep the head from striking the wheel.
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Good work qxman.
To suggest that this advert should be pulled for inadequate scientific accuracy, is just pedantic stupidity, you should see the end rather than the means, after all it isn't the same as an advert for consumer goods that may be misrepresenting a product for commercial gain. In my office there was a discussion about this advert and the general consensus was that everyone would be wearing their seatbelts with vigour after watching it, surely that's a good thing?
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The advert is correct and well done.
doctorchris and qxman; Big Bad Dave seems to disagree, see:
www.honestjohn.co.uk/forum/post/index.htm?t=69638
Edited by jbif on 29/11/2008 at 18:57
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"doctorchris and qxman; Big Bad Dave seems to disagree, see:"
what a tittle tattle
Edited by Webmaster on 04/12/2008 at 00:30
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"doctorchris and qxman; Big Bad Dave seems to disagree see:" >> what a tittle tattle >>
When on the one hand you say
[ www.honestjohn.co.uk/forum/post/index.htm?t=69638 ]
"I hate the current seat belt advert. ... Total crap."
and yorkiebar says: "The advert is wrong!"
and on the other hand doctorchris, qxman, and moonshine say something like:
"Doctorchris - I think you have the correct answer and that the advert is also correct."
"The advert is correct and well done"
then I think it is worth discussing further to find near which end of the polarised statements the truth lies.
Edited by Webmaster on 04/12/2008 at 00:31
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Excuse slight thread drift to surved decellerations! Colonel John Stapp di this for a living!
en.wikipedia.org/wiki/John_Stapp
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I never caught this thread first time round (addicted to a Star Trek site at the moment) or else I wouldn't have posted what I did in the other thread but I agree with the OP.
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No-one has mentioned that in the advert a rib is broken, (from impact with the steering wheel?) puncturing the lung, and leading to death. A likely pneumothorax, if I'm not mistaken, but I'm sure Doctorchris will set me straight, if he/she will pardon the pun! Anyway, what a futile thread. Seatbelts save lives, without doubt. As important, to us all, is the cost to the nation of each fatality, the real reason why the seat belt law was introduced. Accidents cost vast amounts of money when all aspects are taken into account.
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The advert is wrong!
The message is right !
Could it been put across more accuratly? Possibly but would it have achieved the same level of concern that seems to have got through to people who have seen the advert?
My point of view? For once I dont know; I see both sides and not sure whether I want accuracy or more seatbelts worn?
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