During a test crash run, a driverless car speeds up from rest with an acceleration of 6.0 m/s2 for a distance of 108 m. At the end of that distance, it hits a crash-wall. The front of the car crumbles until the car comes to a full stop for a distance of 1.2 m. Find the acceleration rate a test-dummy-driver of this car during the crash, that is during the time when the car hits the wall