Week 14: My thoughts and research of Airbags

Airbags were first introduced in the late1960s. The automotive company, Chrysler, were the first to make a production car with that safety feature. The airbag was invented by John Wenrick, a retired industrial engineer. Since the year 1998, all cars in the United States are required to have airbags on both the driver and passenger sides. According to statistics, airbags reduce the risk of dying or serious injury in a frontal crash by thirty percent. Today, there may be up to eight airbags in a single car.
Before looking at the details of the inner workings of an airbag, we need to understand the laws of motion. Moving objects have momentum unless an outside force acts on the object. A car traveling at a certain speed comes to a sudden stop, objects that are not attach will continue going at that speed. That is why airbags and seatbelts are important to have in order to decrease the risk of death or injuries. Bringing momentum to a halt requires a force acting over a period of time. Airbags are to increase the time of impact and to distribute the force across a larger surface area. Airbags also slows down the speed of the passenger between a small time frame. The time period between the deployment of an airbag is about a fraction of a second.
The airbag inflation system contain three main component: the bag, inflator, and the crash sensor. The bag is made of nylon fabric and is folded inside the steering wheel, dashboard, seats and or doors. The sensor sends a signal to the inflator to inflate the bag when it is activated. The activation itself is a process. Inflation happens when there is a collision force equivalent to running into a wall at ten to fifteen miles. A mechanical switch is activated when a mass shift closes a electrical contact, which alarms the system that an accident occurred. The inflation system contains chemicals that actually ignites and cause a small explosion. Sodium azide reacts with potassium nitrate to produce nitrogen gas which inflate the airbag. The airbag itself is deployed at 200 mph! The gas is then released through the tiny holes in the bag to create a soft cushion for the passenger to land on. This process happens in one-twenty-fifth of a second. Any earlier or later can result in an injury caused by the airbag and not by the car accident. The powdery substance released by the airbag is cornstarch or talcum powder. They are use to keep the bags pliable and lubricated when in storage.
Most up-to-date cars have more than two airbags because a collision can occur at all angles. Side torso airbags inflate between the door and the occupant. These airbags are to prevent any injury to the pelvic and lower abdomen region. Many different design come into play when constructing a side airbag. Manufactures have to shape the airbag to where it can cover a large according to the design of the car. There are also curtain airbags that deploy overhead near the top of the door frame to prevent any head injuries. Some airbags even maintain inflation up to seven seconds for rollover protection. Knee air bags were introduced in 1996 on a Kia Sportage vehicle. The airbag is located beneath the steering wheel to prevent any collision on the lower body.