A block of mass 10 kg moves along a surface inclined 30° relative to the horizontal. The center of gravity of the block is elevated by 3.0 m and the kinetic energy of the block decreases by 50 J. The block is acted upon by a constant force R parallel to the incline and by the force of gravity. Assume frictionless surfaces and let g= 9.81 m/s2. Determine the magnitude and direction of the constant force R, in N.