# Maximum compression of spring.

1. Oct 12, 2008

### bkhofmann

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

I know the mass of the block and it's velocity when it contacts the spring and the spring conststant. It is on a horizontal frictionless surface.

2. Relevant equations

3. The attempt at a solution
I know there is an equation to find the but I just cannot find it in my notes or remember what it is. Can anyone help me out with this one?

2. Oct 12, 2008

### Staff: Mentor

What's conserved?

3. Oct 12, 2008

### dlgoff

The distance if proportional to the force applied.

4. Oct 12, 2008

### bkhofmann

Momentum is conserved since there is no friction, the blocks would fly off at the same speed.

5. Oct 12, 2008

### Staff: Mentor

There's only one block and a spring. (At least, that's what I presume. If not, please state the full problem.) Momentum is not conserved, but something else is.

6. Oct 12, 2008

### bkhofmann

There were two but they are now "perfecly inelastically together. (is there is such a term) and I know the velocity of that new mass. Kinetic Energy is conserved?

7. Oct 13, 2008

### Staff: Mentor

Please get in the habit of describing the complete problem, otherwise we are forced to guess what the issue is. So, I'm guessing, the problem is two masses colliding with a spring between them? (Which is quite different from a mass colliding with a fixed spring.) In that case both momentum and mechanical energy are conserved. (Not just kinetic energy, but spring potential energy as well.)