In fact, the maximum pressure in an airbag is less than 5 psi—even in the middle of a crash event. Advanced airbags are multistage devices capable of adjusting inflation speed and pressure according to the size of the occupant requiring protection.
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How do air bags work step by step?
The bag is triggered by a heavy weight (blue) restrained by a spring (yellow) inside the red cylinder on the right. After an impact, the weight pushes the spring to the right, opening a valve inside a pipe (turquoise) that allows compressed air to flow out from a cylinder (green) and inflate the airbag cushion.
What is the chemical in air bags?
Sodium azide is best known as the chemical found in automobile airbags. An electrical charge triggered by automobile impact causes sodium azide to explode and convert to nitrogen gas inside the airbag. Sodium azide is used as a chemical preservative in hospitals and laboratories.
How do airbags work stoichiometry?
The rapid chemical decomposition of solid sodi- um azide, NaN3, allows the air bag to inflate fast at any time. The decompo- sition reaction is initiated in a car by a small ignition induced by a collision sensing mechanism. The nitrogen gas produced during the reaction inflates the air bag.
How do airbags keep you safe physics?
Air bags. Air bags increase the time taken for the head’s momentum to reach zero, and so reduce the forces on it. They also act a soft cushion and prevent cuts.
Do airbags release chemicals?
They contain chemicals that make the bag open and fill up with air at an incredible speed when triggered by an impact. The main chemicals contained in airbags are sodium hydroxide and sodium azide. When a crash happens and an airbag deploys, dust particles from the chemicals are released.
Why nitrogen is filled in airbags?
Nitrogen is clearly safer and more effective in air bags than compressed air. Analogously, nitrogen inertion helps improve fuel economy of motor vehicles, does not oxidize rubber, and is a safe alternative to compressed air.
Why do airbags have powder?
The residue is primarily corn starch or talcum powder, which is used to lubricate the bag as it deploys, and by-products of the chemical reaction that produces the nitrogen gas to inflate the air bag. This residue may contain a small amount of a potential skin irritant, sodium hydroxide.
What type of reaction is an airbag?
Air bags are not inflated from some compressed gas source but rather from the products of a chemical reaction. The chemical at the heart of the air bag reaction is called sodium azide, or NaN3. CRASHES trip sensors in cars that send an electric signal to an ignitor.
Which gas law do airbags use?
Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, , with excess heat, a large amount of Nitrogen gas () is created.
Why does an airbag contain KNO3 and SiO2?
The nitrogen gas that is generated then fills the airbag. The purpose of the KNO3 and SiO2 is to remove the sodium metal (which is highly reactive and potentially explosive) by converting it to a harmless material.
How do airbags use Newton’s laws?
Newton’s laws enable us to compute the force (and hence the pressure) required to move the front of the airbag forward during inflation, as well as how the airbag protects us by decreasing the force on the body.
How does Newton’s 2nd law apply to airbags?
The main Law at work here is newton’s second law. If there is no equal and opposite force to stop your head from moving, it will keep accelerating like it was while you were driving. That’s where the airbag comes in. Airbags work with accelerometers and explosions in order to save lives.
How do airbags inflate so fast?
The answer would be found in a fascinating chemical called sodium azide, NaN3. When this substance is ignited by a spark it releases nitrogen gas which can instantly inflate an airbag.
Why do airbags smoke?
The “smoke” you may have seen in a vehicle after an air bag demonstration is the nontoxic starch or talc that is used to lubricate the air bag. Air bags are proven, effective safety devices.
How much gas fills an airbag?
Based on the chemical equation 2 NaN3 –> 2 Na + 3 N2, a cup of the compound can easily produce enough nitrogen gas to fill a standard airbag, which is close to 70 liters.
How fast do airbags inflate?
Air Bag Deployment An igniter in the inflator starts a chemical reaction that produces a harmless gas, which inflates the air bag within the blink of an eye – or less than 1/20th of a second.
Are airbags flammable?
The air bag circuit passes an electric current through a heating element, which then ignites a chemical explosive. Older air bags used sodium azide as their explosive to generate nitrogen gas; new ones use different chemicals.
Why do airbags smell burnt?
Airbags may smell smoky but there isn’t necessarily a fire. Small explosives are used to deploy your airbags quickly. They may leave a smoky smell in the air but that doesn’t mean that your car is on fire. If you’re in an accident, the first few seconds and minutes can be disorienting.
Why do airbags smell?
The airbag deploys so suddenly that it can almost feel like your initial collision. It makes a loud pop and emits a very distinct smell of burnt rubber or fabric. It is common to sustain minor burns from airbags as well.
Are airbags endothermic or exothermic?
The performance of airbag and its deployment are based on a fast exothermic-chemical reaction. The hot gas resulting from the chemical reaction which results in airbag deployment can cause thermal damage and skin burning for the car passenger.
What is the secondary chemical reaction in an airbag?
The leftover sodium (Na) is reactive and could be dangerous, so a secondary reaction with potassium nitrate (KNO3) creates potassium oxide (K2O), sodium oxide (Na2O), and more nitrogen (N2).
How do airbags relate to Boyle’s law?
Boyle’s Law- When the airbag expands, the pressure decreases as the volume increases at a constant temperature.
What is gas law chemistry?
The law states that at a constant volume, the pressure of the gas is directly proportional to the temperature for a given gas.
What material are airbags made of?
Airbags are typically made from woven fabric, which may be coated or uncoated but must be impermeable to gases and flame resistant. Nylon textiles such as Nylon (polyamide) 6.6 are among the most common fabrics used to weave airbag cushions for general manufacturing and automotive applications.