Solve Compression Distance for Mass Spring Train Collision

[katysmith]

i have a question in which a train collides with a buffer stop of mass 1.5 tons that asks how far the buffer stop is compressed. this is similar to a block and spring question, except the spring has mass. how is this included in the equation to solve for compression distance?

 

[Mindscrape]

Well, what do your conservation laws tell you? You know that momentum is conserved, and since there are no non-conservative forces at work, then energy will also be conserved.