A spring is used to stop a 50-kg package which is moving down a 20 degree incline. The spring has a constant k=30 kN/m and has no initial compression. It is known that the velocity of the package is 4 m/s when it is 8 m from the spring. The kinetic coefficient of friction between the package and the incline is 0.2. Determine the deformation of the spring in bringing the package to rest.