1. The problem statement, all variables and given/known data Two blocks A and B are connected by a spring of spring constant 1000N/m. Block A is 2kg and has a rightward velocity of 5m/s. Block B is 3kg and has a rightward velocity of 10m/s. When block B collides with block A, there is a maximum compressional force on the spring. What is the length of the spring x at the instant of maximum compression? 2. Relevant equations W = 1/2kx2 3. The attempt at a solution Initial velocity of Block B = 10m/s Velocity of Block B at the instant of collision = 0m/s Change in kinetic energy = 1/2(3)(10)2= 150J 150 = 1/2(1000)(x)2 But my answer is different from the answer provided, can anyone tell me where did i go wrong? Thanks.