In a car collision, is it better for the passenger if the change in momentum is over a short period of time or a long period of time?

Explanation:

The force on the passenger will be F = ma

Here, m does not change, but a is the variable.

If the cars slows down very fast, the acceleration will be higher, and thus the force will be higher.

If the acceleration is lower, the force will be lower as well, which would be the most desirable scenario for the passenger.