Two masses are connecte by a ligh string over a light, frictionless pulley the table surface that m2 is on is also frictionless. Apply the work-energy theorem for this system to calculate the speed of the masses after the masses have moved a distance delta x starting from rest. Note that the work of the tensions drop out. Use the result to obtain the acceleration of the system. I've looked at this problem for a while now and I just don't know how to get the work of the tensions to drop out given that if m1 is that mass that's hanging and the forces working on it is F= T1-m1g and the forces working on the mass on the table (m2) is N-mg=ma=0 and T2-m2g=F... yeah. I understand that F=ma and that W=dF= 1/2mv2 but I just can't seem to understand how the tensions fall out of the equasion..