The steel ingot has a mass of 1800 kg. It travels along the conveyor at a speed v = 0.5 m/s when it collides with the "nested" spring assembly. If the stiffness of the outer spring is k(A) = 5 kN/m, determine the required stiffness k(B) of the inner spring so that the motion of the ingot is stopped at the moment the front, C, of the ingot is 0.3 m from the wall. (Outside spring A is 0.5 m long and the inside spring B is 0.45 m long.)