1. The problem statement, all variables and given/known data In the figure below, block 1 (mass 1.6 kg) is moving rightward at 8 m/s and block 2 (mass 4.2 kg) is moving rightward at 2.8 m/s. The surface is frictionless, and a spring with spring constant of 1120 N/m is fixed to block 2. When the blocks collide, the compression of the spring is maximum at the instant the blocks have the same velocity. Find the maximum compression. 2. Relevant equations mv+mv=mv not sure what spring equation is needed. 3. The attempt at a solution Tried taking the velocity of the sytem them puting that in to kinetic energy = spring energy but that was not right.