Linear Momentum Block and Spring Problem

[shaggyace]

Homework Statement

A 0.500-kg block is attached to a horizontal spring that is at its equilibrium length, and whose force constant is 23.0 N/m. The block rests on a frictionless surface. A 5.60×10^-2 kg wad of putty is thrown horizontally at the block, hitting it with a speed of 2.00 m/s and sticking.

Homework Equations

p=mv

KE=0.5 mv^2

PE=0.5 kx^2

vf= (m1V1,i + m2v2,i)/m1+m2

The Attempt at a Solution

I tried finding the kinetic energy of the wad of putty as it hit the spring and I got 0.112. I then used this as the PE of the spring and solved for x in the PE equation getting 0.099 m. I know that this is wrong however. I just don't know how to attack this problem.

 

[shaggyace]

Never mind everyone , I figured it out :)