Inelastic Collisions: Solving for Spring Displacement

[patelkey]

Homework Statement

In the figure below, block 2 (mass 1.4 kg) is at rest on a frictionless surface and touching the end of an unstretched spring of spring constant 170 N/m. The other end of the spring is fixed to a wall. Block 1 (mass 2.0 kg), traveling at speed v1 = 4.0 m/s, collides with block 2, and the two blocks stick together. When the blocks momentarily stop, by what distance is the spring

Homework Equations

m1v1=m2v2

The Attempt at a Solution

I attempted the solution but I am confused about the 170N/m
How would I use that information and relate it to the equations of inelastic collision?

 

[rl.bhat]

Find the velocity of the combined blocks after collision. Then find the KE of the the combined blocks.
What is the expression for the energy stored in a compressed spring?

 

[patelkey]

ohhh okk i got it
I had to use W=1/2kx^2
they gave k and i figured out W through the KE equation.
it was 0.33 m if you were curious.