Who can help me with a physics/dynamics problem?

Two blocks, a fritionless plane incline at angle theta, an ideal pulley, and a lenght of ideal rope comprise the dynamical system shown in the nearby figure. The masses of the blocks are: M1=M and M2=M/2. At t=o the system of blocks is in motion “upward” at speed Vo. 

I found the acceleration and the tension of the rope; however, I don’t know how to determine how far each block has displaced from its original position at t=0 at the instant the system comes to [instantaneous] rest.

Further information will be provided such as the solved acceleration and tension if you are able to help me.