1. The problem statement, all variables and given/known data A block of mass m1 = 4.0 kg slides along a frictionless table with a velocity of +10 m/s. Directly in front of it, and moving with a velocity of +3.0 m/s, is a block of mass m2 = 9.0 kg. A massless spring with spring constant k = 1120 N/m is attached to the second block as in the figure below. After the collision, the spring is compressed a distance X, find X. (Attempt at a drawing) block1 Spring.....Block 2 [m1] |--/\/\/\/[m2] Everything is moving in the +x direction, or to the right. 2. Relevant equations 1/2*m*v^2 1/2*k*x^2 Pi=Pf P=m*v 3. The attempt at a solution I thought that you would use the difference between their KE's to find the PE stored in the spring. However, when I run the numbers into the equation PE = KE1-KE2. I end up getting slightly over. So I'm doing something wrong and I cannot find where it is at. Edit: I accidentally hit backspace and reloaded the page, so it freaked out and copied everything.