A red block with a mass 0.25kg slides on a horizontal frictionless surface at 3m/s. The red block then rear ends a green block (.35kg) that is initially at rest. Due to some Velcro the blocks slide together after the collision. They slide into a horizontal spring that has a spring contain of 2000N/m that is initially relaxed. How far is the spring compressed before the blocks come to rest? (Answer: 0.022m)