**1. The problem statement, all variables and given/known data**

In Fig. 9-64, block 2

(mass 1.0 kg) is at rest on a

frictionless surface and touch-

ing the end of an unstretched

spring of spring constant 200

N/m. The other end of the spring is fixed to a wall. Block 1 (mass 2.0 kg), traveling at speed v_{1} = 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 compressed?

**2. Relevant equations**

m_{1}v_{1}+m_{2}v_{2}=MV where M is the mass of the system and V is the velocity of the system

Hooke’s Law: F = kx

**3. The attempt at a solution**

I was able to find the final velocity of the system:

V = (m_{1}v_{1})/(m_{1}+m_{2}) = 2.974

How do I get from there to the distance that the spring is compressed?

http://ift.tt/1ewvcRT