1. The problem statement, all variables and given/known data http://img187.imageshack.us/img187/9476/dib.th.png [Broken] mA = 22kg mA = 10kg No friction At t = 0, at rest a.- Find aB b.- Find vB/A at t = 0.5s 2. Relevant equations 3. The attempt at a solution http://img504.imageshack.us/img504/3786/dib3.th.png [Broken] http://img504.imageshack.us/img504/9979/dib2.th.png [Broken] I got to the following equations: mA·aA = mA·g·cos(30) + NB·sin(50) 0 = NA - mA·g·sin(30) - NB·cos(50) mB·aA·sin(30) = NB - mB·g·cos(20) mB·aB/A - mB·aA·cos(50) = mB·g·sin(20) There must be something wrong in these because after solving my results are wrong. I don't know if I chose the wright base for studying each body (maybe the equations would be simpler with some other base?). Thanks for your help!