How do airbags work?

The airbags in our cars work by decomposition reaction. Weird? Right... When our car hits a lamp post or some other things, it took 50 milliseconds for our head to hit the steering. Thus, by using this calculation, they designed air bags to open in 30 - 40 milli seconds and thus it helps our head and it saves us from injuries. When there is a collision, the sensors called accelerometers detect it and send electric signals to the ignitor. This ignitor ignites a chemical called Sodium azide which decomposes and produce sodium and large volume of nitrogen gas. This gas instantly inflates the airbag. This whole process take about just 30 to 40 milli seconds to happen. Thus, air bags helps to save our lives in cars. There is no invention still developed to save our lives from motor cycle. So kindly use helmets to prevent serious injuries while riding two wheelers.