The 50 kg block at A is mounted on rollers so that it moves along the fixed horizontal rail with negligible friction under the action of the constant 300 N force in the cable The block is released from rest at A with the spring to which it is attached extended an initial amount X_1 = 0.233 m The spring has a stiffness k = 80 n/m. Find the velocity of the block as it reaches position B. Use the work-energy method.