1. The problem statement, all variables and given/known data Basically I want to know what material (That I could easily access) would be great to minimize impulse in the following situation: A car is placed at the top of a ramp with some angle less than 45 degrees and at its front there is a tracker that measures the amount of force put into the car once it runs into the wall. I can add some material/compound to the front with the dimension 10x15x15 cm where 10 is the dimension in line with the length of the car. (Foam is not allowed) 2. Relevant equations p = mv J = Ft 3. The attempt at a solution Obviously I know that I need to minimize J (impulse) and maximize t (time), and I've thought of a few materials but I'm looking for any that you may have come across in your life that could help.