How do I properly set up this F.B.D.?

1. Oct 10, 2016

Vitani11

1. The problem statement, all variables and given/known data
A uniform solid cylinder of wood rolls without slipping down an incline of angle theta. the coefficient of static friction is μs and kinetic friction is μk. Find the acceleration of the center of mass of the cylinder.

2. Relevant equations
mgsin(theta)-μk = ma

3. The attempt at a solution
My question is really how to reconcile with the static friction coefficient. Should this be included in my FBD and so my equation? Or would I just be using the μk and not the μs? If μs is to be included, can you please explain how? Would I have to set up two equations, one to overcome the static friction and the other to characterize the rolling motion with μk, then solve for the acceleration using a two-equation system?

2. Oct 10, 2016

Staff: Mentor

You are told that the cylinder rolls without slipping, thus the only friction involved is static friction. (Hint: Write two equations: one for rotation, one for translation.)