How Airbags Work

Airbags have saved plenty of lives (thousands a year) and are the last defense to you surviving a high-speed impact. However, many people do not know how airbags work and what specific requirements make an airbag come out. This is important to know because you do not want to be afraid that any impact to your car will cause an airbag to go off.

The Physics of Airbags

Everything that happen in the world is due to physics. Car collisions are due to the laws of motion. Generally, everyone knows that the more speed (velocity) you have, the more kinetic energy you are going to have (especially if you are a body with a lot of mass). So, if you are 10 pounds and moving and 20mph, and someone weighing 20 pounds but moving at 10mph will even out. If the 10-pound person were to be moving just 1mph more, then they will make the other object move with (it wins the collision, kind of). Now let’s do this with cars. With a head- to-head collision, the kinetic energy (energy made from movement) from both cars are added up, thus making the impact worse. However, the reason an airbag is triggered is not because of the force of impact, rather, it triggers because of the drastic change of momentum. There is a chip in a car that detects changes in speed, and if you are going really fast (let’s say 70mph) and hit someone, you are going to slow down real fast. Once that happens, your airbags come out because you slowed down way too fast (braking from high speeds will not make your airbag come out). To test this, buckle up and leave a plastic bottle on the passenger seat that isn’t buckled up or restrained, drive on an open road (just at normal speed) and hit the brakes abruptly. The seatbelt should reduce your speed gradually but the water bottle should fling into the dashboard at that same speed that you were at before you hit the brakes. The only reason you can survive a high impact collision is because the seatbelt and airbags displace the full impact over time. The more time in between an impact, the less damage you will take.

The obvious trade back about airbags are that their force can seriously injure someone. Airbags can be fully inflated in a fraction of a second. There are thousands of reports of an airbag adding to the injuries because a person’s face can travel to the steering wheel faster than an air bag if they were traveling fast enough. An airbag can save your life, but it has to be calculated correctly to cause little to no harm. Sometimes, you will have to get a fractured nose or acquire bruises if it means your life is saved. Of course, this doesn’t happen more than coming out of an impact unharmed, so airbags do their jobs effectively. To avoid getting injured, set your seat to the rear as much as possible, but still where you can comfortably steer and reach the pedals.

For children, airbags can be detrimental. Make sure that children 8 and under are properly buckled up and have a car seat or booster seat. Since children’s bodies are not as developed and cannot take an airbag impact as well as adults. Those are the basics of how airbags work and why physics make airbags a necessity. By trying to regulate you speed at or under the speed limit, keeping your seat back, having your seat belt on, and driving cautiously will prevent any major impacts or injuries.