1. The problem statement, all variables and given/known data Literally #19 from this link: http://physics.ucsd.edu/students/courses/summer2007/managed/physics2a/documents/chp6.pdf [Broken] The figure is not within the .pdf file, so I recreated the figure it references: http://img32.imageshack.us/img32/5701/figurephysics.png [Broken] 2. Relevant equations [tex] F = ma [/tex] 3. The attempt at a solution Working the problem on my own, I only am able to get to this step, where the tension forces cancel: [tex] m_ra + m_la = m_rg\sin(20) - m_lg\sin(60) [/tex] ... I am at a loss for the next step; particularly in the demonstrated solution, where they add and subtract the acceleration.