Acceleration of a Pulley System?

[allsmiles]

Homework Statement

Body B in the figure weighs 102N and Body A weighs 32N, The coefficients of friction between B and the incline are Ms=0.56 and Mk=0.25. Find the acceleration of the system if
a) B is initially at rest
b) B is moving up the incline
c) B is moving down the incline

Homework Equations

i don't understand which equations i would need

The Attempt at a Solution

what's the difference in situation between a, b, c i don't understand how i could solve them differently
i am so confused!

 

[allsmiles]

this is the original question example 5
i get how to get the acceleration, but what's the difference between part a,b,c

opps: forgot the link: people.uncw.edu/ganl/phy201
go to chapter 6, example 5:)

 

[pgardn]

this is the original question example 5
i get how to get the acceleration, but what's the difference between part a,b,c

opps: forgot the link: people.uncw.edu/ganl/phy201/chapter_6.ppt

I gave a post about this on the other problem.
Your link does not work so if someone else wants to help tonight you might want to change it.