Solve Basic Spring Problem: Minimum Distance Between Connected Blocks

[fireemblem13]

Tell me if this question makes any sense.

One block moving with velocity v_0 hits a system of two blocks at rest connected by an undeformed spring with spring constant k. Find the minimum distance between the blocks attached to the spring. All masses are of equal mass.

I'm not quite sure what to do with this. I don't see what's limiting the distance between the blocks.

 

[tiny-tim]

Welcome to PF!

Hi fireemblem13! Welcome to PF!

Block A is moving. There is a spring between blocks B and C. The spring will stop B from hitting C.

 

[fireemblem13]

So, it's asking the minimum distance B and C can be so that B does not hit C when A hits B?