The trajectory of a falling rock is mainly determined by bounces on the ground or with trees reducing continuously the rock's kinetic energy thus braking it. Free fall experiments on a horizontally positioned concrete slab covered by a special cushion system allow an analysis of the braking process. The process has been recorded using high-speed video and acceleration sensors attached to the rock. These interdependent measurements allow deduction of the kinetic process, i.e. velocity and displacement, obtained from integration of the rock's acceleration and independently from differentiating the video displacements. This contribution shows the validity of both methods and additionally suggests how to evaluate and to classify e.g. novel cushion systems.