A block with mass m1 = 8.8 kg is on an incline with an angle ? = 39.0° with respect to the horizontal. For the first question there is no friction, but for the rest of this problem the coefficients of friction are: ?k = 0.38 and ?s = 0.418. To keep the mass from accelerating, a spring is attached. What is the minimum spring constant of the spring to keep the block from sliding if it extends x = 0.12 m from its unstretched length.