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is this even physically possible?
  [vote for,

A mass is kept in the front of your car, and when need be, is propelled backward on a rail and caught by some braking system in the rear (or vice versa if the physics dictate it need be... I've never really been a whiz at physics...) thus creating a force on the vehicle in the opposite direction equal to the force of the vehicle in the forward direction (this can be done now with all of the whoosits and whatsits of the electronic world). This might allow for a one-shot emergency break that neither damages the road, nor any other vehicles (permitting that all vehicles would be equipped with it, which is, of couse, an impossibility, but we can sure hope). As for the people, I imagine that some kind of similar breaking system could be rigged up for the chairs, or they could just, of course, wear their seatbelts.
Soulr, Feb 09 2003

(?) Deceleration Trauma http://usff.com/BOL...ticles/0198pan.html
"It's not the fall that kills you, it's the sudden stop at the end" [Cedar Park, Oct 04 2004, last modified Oct 21 2004]


       If you mean 'on the spot' as in 60-0 in less than a second, this is physically impossible (without seriously injuring the occupants & vehicle).   

       In order to generate this force, which would actually be something being launched in the direction of the motion if you remember your high school physics, a very large mass would have to propelled forward, making a dangerous situation for the driver and surrounding cars/pedestrians.
Cedar Park, Feb 09 2003

       You then have a large weight travelling forward in an uncontrolled manner with the same momentum your vehicle had originally. Great for you, not so great for anyone in its path. Might as well buy a Volvo if you think that way.   

       And watch out for the car behind!
egbert, Feb 09 2003

       a friend of mine gave me a very reasonable response to this whole thing. He is right that if a weight were to create this kind of force, it would have to be quite substantial, and that such a force would likely rip the car in two... kinda bad when it's supposed to be a safety device...
Soulr, Feb 11 2003

       Aside from the safety issues, the weight that would be needed for this mechanism really couldn't help the cars fuel efficiency.
RoboBust, Feb 11 2003

       Shifting the centre of mass of a vehicle to protect the passenger cabin is a great idea. It's been done (to a small extent) by a European car manufacturer. Which one it was has temporarily slipped my mind (might have been Saab or Audi) but I will google. If memory serves, they fitted the engine block on rails, fastened with weakened bolts that sheared during a high speed crash. The engine slid forward inside the car, increasing the time of the accident and lessening the peak forces. I think it also dragged the steering column with it, reducing driver head injuries. (I'll have a google and see if I can find it). (Some googling later... no sign of it. Anybody heard of this, bar me?)
st3f, Feb 11 2003

       [st3f] It was Audi's Procon-10 system IIRC. From what little I can find about it, it was phased out with the introduction of airbags.
oneoffdave, Feb 11 2003

       // I've never really been a whiz at physics. // It shows with this suggetion. Aside from the safety concerns raised by others reguarding a large mass being flung from one point or another to induce/counter inertia, where is the power comming from to move the mass in the first place? The larger the mass, the more force is needed to move it.   

       Consevation of energy, there's no such thing as a free lunch.
ato_de, Feb 11 2003

       /This might allow for a one-shot emergency break that neither damages the road, nor any other vehicles/ and knocks the 'ass' out of the rapidly accelerating car... sure hope he lives.
X2Entendre, Feb 11 2003

       The power that propels the mass backward would be better used for virtually anything else, such as stopping the vehicle.   

       If something is in front of you, and is propelled backwards quickly, isn't that thing going to crash into you?
waugsqueke, Feb 11 2003

       Isaac Newton, Circa 1640 (or thereabouts): "For every force there is an equal and opposite reaction" to paraphrase.   

       (not to mention the laws of conservation of momentum)   

       Meaning that when the "strangebrake" is fired, the car's chassis is actually accelerated forwards as a direct response to the mass being flung backwards. As soon as the mass hits the stops at the back of the car, the car will once again become a solid battering ram (and it will now be travelling at its original speed again, more or less). Mounting it back to front will not improve matters one iota although the sequence of events will change.   

       This contraption may well bring about interesting new forms of whiplash, thus ensuring the medical profession a healty turnover.   

       This suggestion, although imaginative, is apt for a website entitled "Halfbakery". No offence meant ;)
wossy, Feb 11 2003

       now that suggestion, unlike many of the other "unnecessary" and demeaning ones sheds light onto why this system will not work. Thank you for pointing that out (and I do not delete suggestions by anyone, no matter how unhelpful their comments are)
Soulr, Feb 12 2003

       Soulr, don't get discouraged so easily. Take all of this advise and use it. Everyone misinterpreted your idea because the only physically possible way for an idea such as yours to slow down a car is if the mass was launched in the forward direction. Sure, everyone found problems with launching a projectile at the other car, but at the halfbakery there's always a way around problems. Who says the projectile has to be a dense hard weight? Maybe you launch a whole lot of expanding foam forward at a very high velocity. Not only would the foam not hurt the other car, but if it was of an extremely quick-hardening variety might be an additional cusion between you and the object you may hit. Sure, you'll have to pay the dry cleaning bill of the pedestrian you almost hit, but isn't that a good price for safety?
Worldgineer, Feb 13 2003

       There was an idea for a kinetic water-jet decelerator around somewhere on the HB..... can't seem to find it. The suggestion was projecting a reatively small mass of water forward at very high velocities (using a propellant charge). Can't seem to find it.
8th of 7, Feb 13 2003

       youre right worldgineer, perhaps there is another solution. I was toying around with the idea of a liquid gas thrown forward that upon exposure to air converted back into gas form, yet the mass has still been technically "flung" forward. Thanks :)
Soulr, Feb 13 2003

       [Soulr] Careful with that idea - you'll rapidly cool whatever the liquid hits. The other car (or even pedestrian?) might just shatter like glass.
Worldgineer, Feb 14 2003

       perhaps if the roads were constructed with a type of magnetic element. The front of the car could have two huge magnets on a spinning rod. And when engaged the magnets could spin at the right angle and actually help propel the car in the opposite direction in which you are traveling. I am not sure what ends attract on two magnets but make it so it basically helps slow down. Also have to construct it so it wouldnt slow you down to a point then pull you right into the car in front of you.---If that were the case place the magnets in the middle of the car directly underneath.
OriDea, Feb 02 2007

       People with better brakes than the guy they are in front of tend to get rear ended more often.
Jscotty, Feb 02 2007

       Sorry, but as it has already been said, there is no free lunch. The force used to push the weight backward automatically moves the car forward, and since the car and the weight are already moving, this solves nothing as the weight simply moves within the car. It doesn't work.   

       I suppose it could be used to get a car out of a ditch easier (you know, moving ballast), seeing as the motion created by the weight could be pushed off the snow (by way of the car's wheels). This weight would only work in situations where there was something to push off.
trimothien, Feb 02 2007

       One way to accomplish a quick stop would be to mount rockets pointing out of the front of the car. This has the disadvantage, though, of requiring lots of explosive chemicals to be stored in your car. Also, I imagine that street racer types might take them out and mount them at the back of the car for more acceleration.
discontinuuity, Feb 02 2007


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