Explanation:
Impulse is the change in momentum. It is also equal to the average force times the change in time.
J = Δp
F Δt = m Δv
The change in momentum is a fixed number; your mass, initial velocity, and final velocity are constant.
F Δt = k
So force and time are inversely proportional. What this means is, we can either have a large force over a short period of time, or a small force over a long period of time.
Obviously, we want a small force over a long period of time. Without airbags, your head would hit the steering wheel very quickly. With airbags, your head has time to decelerate, so there's less force.
