The spring has a stiffness k and an unstretched length l0. As shown, it is confined by the plate and wall using cables so that its length is l. A block of weight W is given a speed v_A when it is at A, and it slides down the incline having a coefficient of kinetic friction μ_k. If it strikes the plate and pushes it forward a distance l₁ before stopping, determine its speed at A. Neglect the mass of the plate and spring.

Given: W = 4 lb lo = 2 ft 1 = 1.5 ft 41 = 0.25 ft d = 3 ft k = 50 Mk = 0.2 a = lb ft 3 b = 4 W