What is the actual physics of a car crash, and its involvement with the crumple zone, safety belt, and air bag
953552
The "the complete physics of a car crash" would be a very long and complicated answer.\nHowever, the specific items you mention (crumple zone, safety belt, air bag) all serve a common purpose in the event of a crash...to lessen the force which is applied to the car/passengers/... at any given in the event off a crash.\n\nImagine you are in a car driving at 60 mph and you run into a solid brick wall.  One way or another, the car and its contents are going to stop.  The faster the stopping action happens, the larger the force acting on the car and the more harm can be done.  If the crash / stopping action occurs very quickly, the change in the overall object's momentum occurs very quickly and results in a large force.  But if you slow down the crash, even for a few fractions of a second, it can significantly reduce the instantaneous force acting on the object, even though the overall impulse applied to the object is the same.\n\nBy using crumple zone, the car "crumples" as it hits something, which slows down ow fast the car comes to a stop.  Using a safety belt and air bags work in a similar fashion to slow how fast a passenger comes to a stop by cushioning the impact.\nThe more effective "padding" is used, the smaller the force experienced by the object.  Think of it like an falling onto a concrete floor versus falling onto a pillow.  The pillow "gives" more on an impact whereas the concrete floor doesn’t move much at all and the impact happens very suddenly.  An eggs will almost certainly break if hitting a concrete floor, but stands a good change of survival if it falls onto a pillow thus illustrating the lessening of the instantaneous force acting on the object even though in both cases the result is the same...the egg comes to a stop.
553994
1st - An object in motion/rest will stay in/at motion/rest unless acted upon by another force.\n\nExamples - a ball will keep rolling until its friction with the ground stops it. A rock will stay put unless someone transfers energy to it to move it.\n\n2nd - Force = Mass x Acceleration\n\nExamples - Some car has 5000 kg mass and 10 m/s^2 acceleration. Find its force.\nForce = 5000 x 10\nForce = 50,000 newtons\n\nSome truck has 250,000 newtons of force, and an acceleration of 5 m/s^2. Find its mass.\n250,000 = Mass x 5\nMass = 250,000/5 = 50,000 kg   \n\n3rd - For every action, there is an equal and opposite reaction. \n\nExample - you bounce a ball on the ground. The ball hits the ground, and compresses inward. The ground pushes back up on the ball causing it to land in your hands. You hit a volleyball in PE. The ball pushes against your hands and goes over the net.
1160918
Popular Mechanics Article here:\nhttp://www.popularmechanics.com/science/defense/1227842.html\nPentagon Site here:\nhttp://www.abovetopsecret.com/pages/911_pentagon_757_plane_evidence.html\nStructural failure report by NIST here:\nhttp://wtc.nist.gov/\n\nA little common sense will get you thinking the right way.  Good luck.
1088799
1.  Meteorology - i.e. the day's chance of rain\n2.  Product Testing - i.e. does a car perform within a certain realm of safety?\n3.  Quality Control - i.e. does your turkey sandwich really average 1 oz of meat?\n4.  Inferential statistics - i.e. based on sample data, what is that jerk-off in the car in front of you planning on doing, considering he's going 80 in a 40 mile zone and traffic is at a dead stop in his lane in 40 feet?\n5.  Surveys - i.e. customer satisfaction of a particular store or use of a product.
932299
check out the national highway traffic safety administration.\n\nthere are numerous studies and statistics about the use of seat belts.
937731
Because the faster a vehicle goes, the greater the momentum.\n\nMomentum = mass * velocity, so it increases with velocity.\n\nWhen you get in an accident, and if your car is brought to a sudden stop, you still have this momentum, this velocity. If you are not strapped down, then your movement, at the velocity continues, regardless of the new post-accident velocity of the car. If it is stopped then you will impact the instrument panel and windshield with the same velocity and momentum you had.\n\nIf you have an accident without a seatbelt, without airbags, you will get seriously messed up. And the faster you are going, the worse off you'll be.
339530
The only people you should speak to about your accident are the police, your insurance company, and your lawyer. Never give out any personal information over the phone. \n\nIf in fact the air bag did malfunction your insurance company should be able to guide you through what needs to be done. The government would have nothing to do with it.
673018
Considering the physics laws, we have:\n\nv = vo + gt, where \nvo - initial speed (m/s)\nv - final speed (m/s)\ng - gravitational acceleration (9.81 m/s*s)\nt - time (s)\n\nI can assure you'll not obtain a crater, but you can kill a people.
4088
because the air inside the car is moving with the car
316643
Go to a dealership and have the problem inspected.  It could be related to another problem with the vehicle but if there is problem with the air bag it could end up being fatal in an accident.
920180
Call a lawyer, but I'll bet you're going to have a hard time winning.\n\nAirbags are designed to deploy only when certain things are present and if any one of those things aren't present then the airbags won't deploy. \n\nYou said you hit the concrete wall head on, how fast, head on at an angle? Did you modify the car in anyway? And remember airbags are only supplemental only not primary so you were wearing a seat belt right?\n\nAnd even if you get a lawyer and s/he agrees to take it on contingency you are responsible for all expenses.\n\nWell, be thankfull you're alive.
802571
wow...in 1968 i watched what appeared to be a shiny metallic piece of  crumpled metal tumble towards earth for 10 minutes, it was probably space debris or toilet ejecta from a passing airliner.what you seen was likely hardboard insulation like they use on construction sites, that stuff will fly a long ways with little wind....or else it was a runaway magic carpet
414000
Safety belt (seat belt) of a car - This is my answer, if you have some funny answer let us know
834476
No energy is lost as a result of heat or material deformation in an elastic collision.  It simplifies the mathematics by not having to keep track of non-motion energy, but it does not reflect practical results.\n\nIf automobile collisions were totally elastic, body shops would be out of business but funeral homes and hospitals would have a boom.
112793
This is a scary thought, but it depends on the way(or area) of the impaction. For example, if you were traveling at a high speed(say 75-80 mph) and were hit from behind, it would be best to not have on the seatbelt...because you would have better chances of surviving if you were thrown out of the car! But, if you were traveling at a relatively low speed(35-40) and were hit from the side or something, it would be best to wear the seatbelt! It really just depends on the situation! Most who street race etc. do not wear seatbelts because they know that they are going to be traveling at high speeds and have a better rate of surviving not wearing the belt. But, that being said, most of us do not drive that fast and the instances where seatbelts did more harm than good are rare...so, always where your seatbelt!!!
14955
(a) it's an inelastic collision.  An inelastic collision is when they stick together, and an elastic collision is when they bounce off of each other\n(b) p=mv  momentum= mass x velocity.  p= 30 m/s x 500kg = 15,000 kg*m/s\n(c) well, momentum is conserved, so the we would use the formula from before and the momentum(p) from before, except that now the mass is different because it is the combined masses of the two vehicles (300+500=800) , so you can solve for the new velocity.\np=mv  15000 = 800 x v\n\ndivide both sides by 800 to get  v=15000/800 = 18.57 m/s
541091
Inertia means two things:\n\nAn object at rest will stay at rest, unless another force acts on it.\n\nAn object in motion will continue in motion, unless another force acts on it.\n\nAny force which changes the motion of an object -- the speed and/or direction -- is called acceleration.\n\n...You're riding along in your car.  Both you and the car have inertia; that is, you're both in motion, and will continue to move until something changes that.\n\nThe car runs into a wall, which certainly makes a big change in the car's motion.  You, on the other hand, and anything else inside the car that wasn't strapped down, will continue to move forward because of your own inertia.  Without a seat belt or air bag, your body will continue to move forward through the windshield, which is undignified, extremely painful, usually fatal, and a big drag to clean up.\n\nSo:\n\nA)  Seatbelts put you more "in contact" with the car; which is to say, any force which affects the inertia of the car will be more efficiently transferred to your body -- though not *so* efficiently that you go "splat" like the rest of the car; they just restrain you from continuing forward into the windshield.\n\nB)  A head rest acts as an accelerator for your head.  If the car accelerates suddenly (such as when somebody runs into the back of your car), the car's seat transfers that acceleration to your body.  The head rest acts as an extension of the seat, so that your head is also accelerated and doesn't get "left behind" because of its own inertia.\n\nC)  In practical terms, a force which is applied directly opposite to an object's direction of movement is called "deceleration."  It's still the same thing as acceleration, but we treat it as if the speed an object is going in a particular direction is being decreased in the same direction.  When the car hits the wall, as your body's inertia propels you forward, the air bag acts as resistance to that forward movement, decelerating the forward motion of your body.\n\nThe point to all three of these is to gently transfer acceleration to your body.  A car is much more rigid than your body (for instance, if you were to accelerate really hard, the rear bumper isn't going to get left behind), and is able to take much more drastic changes in its speed and direction.  Your body is much more fragile (and much more valuable) than a car, so seat belts, head rests and air bags are used to ease the changes in acceleration.\n\nAs you know, falling off a tall building isn't what kills you, it's the big fat splat at the bottom.  When you fall, your body accelerates down with a force of one G (which stands for earth's gravity), which your body can handle quite well.  But when you hit the ground, the ground acts to accelerate you in the opposite direction (up) *very* quickly, with much more acceleration than your body can stand.  If there's a big enough air bag to land on, it will slow down the up-acceleration (or down-deceleration, whichever way you look at it) to something that your body can handle.  Now, turn the whole setup sideways, and that's the reason for seatbelts, air bags and head rests.