Galileo Galilei is an important forefather to much of what we know today about physics and astronomy. In fact, he was one of the first people to claim that the sun was the center of the universe, not the Earth. He was also the first to use the telescope to examine celestial bodies. Finally, he realized that in a vacuum, if two different weighted objects were dropped, they would land at the same time. Those are just a few of his many accomplishments.
Heres a simple answer Galileo Galilei was an Italian polymath. Galileo is a central figure in the transition from natural philosophy to modern science and in the transformation of the scientific Renaissance into a scientific revolution.
Since the goal of the airbag is helping the person to stop after the collision in a greater time, this means that the change in momentum must finish when this is just zero.
In other words, the change in momentum, must be equal to the initial one, but with opposite sign.
Now, just applying the original form of Newton's 2nd Law, we know that this change in momentum must be equal to the impulse needed to stop the person:
So, as we know the magnitude of Δp from (1) and we have different Δt as givens, we can get the different values of F (in magnitude) required to stop the person for each one of them, as follows: