1. The problem statement, all variables and given/known data A uniform circular pulley of mass 2m can rotate freely about its axis of symmetry which is fixed in a horizontal position. Two masses m, 3m are connected by a massless string which passes over the pulley without slipping. The whole system undergoes planar motion with the masses moving vertically . Take the rotation angle of the pulley as generilesed coordinate and obtain Lagrange's equation for the mtoion. deduced upward acceleration. 2. Relevant equations 3. The attempt at a solution 3Mdv/dt=3Mg-T Mdv/dt=T-Mg deltaH=a*delta(theta) v_c=v-a*omega Sigma=T*dr=0 r x Mg(-y-hat)=0 pulley is frictionless. Seems like the only thing I should do would be to find T which would help me find the acceletion for M.