Airbag

Airbags are large nylon bags, neatly folded away and hidden until a car has a crash. They sense when to inflate, using devices called accelerometers around the car, which detect any sudden slowing down. If the slowing down is sudden enough, a small explosive device goes off, releasing nitrogen gas that fills the airbag, which cushions the blow for anyone in the car. This all happens in the blink of an eye, or around four hundredths of a second. Most cars now have six or seven airbags placed around the car in different places to help protect everyone travelling inside.