Question

how do airbags use the physics concepts of energy?

Answer 1

Airbag uses the concept of increasing the impact time thereby decreasing the force.

Assume there was no airbag. Upon a accident the driver will be set on motion towards the windshield on applying brakes i.e., the driver will be set to stop after hiting the shield. This creates a huge force as the impact time is very small.

We know from Newton's law

As impact time is very small force is huge causing greater damage.

Now, if airbags are deployed the person will hit the airbag and the time required for the driver to hit the windshield is highly increased due to the air barrier. So, force is heavily decreased thereby decreasing injury caused.