How does an airbag protect a passenger in a car accident?

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

Although longitudinal waves can travel through all media types what is the disadvantage of this type of wave transmission? a) he efficiency of he wave transmission is greatly diminished as the media becomes less dense b) the oscillation of one set of particles has a huge impact on neighboring particles c) particles become too close together as they bump into each other making it more likely to hit other particles down the line

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up