Impulse & Momentum: Solving Homework Problem

[duperduperman]

Homework Statement

http://courses.washington.edu/mengr230/sp11/handout/n25_ImpulseMomentum.pdf
the problem at the bottom

Homework Equations

on the link

The Attempt at a Solution

I wrote out the equation and I don't really know where the friction factors in. I'm pretty much 100% lost on this. I've done a good amount of impulse and momentum problems but this one is stumping me.

 

[Brand3n]

I wrote out the equation and I don't really know where the friction factors in. I'm pretty much 100% lost on this. I've done a good amount of impulse and momentum problems but this one is stumping me.

The Uk is for kinetic friction and the Us is for static friction. Static friction is when it's not moving and kinetic friction is when it is moving.