1. The problem statement, all variables and given/known data Find an expression for the acceleration of m1. 2. Relevant equations 3. The attempt at a solution I did this earlier, and looking back on it I have a question: Sum of forces for m1: Fx= F2 on 1= m1a1 Sum of forces for m2: Fy = F1 on 2 + T1 - m2g = m2a2 I got the expression after substituting them into each other and saying a2 = -.5a1, I'm just wondering why you can say T1= F1 on 2 , because since there is acceleration, can you consider the tension throughout the rope to be the same?