1. The problem statement, all variables and given/known data This is my first time using this forum so I'll try to start this off right. The question is this : Two masses, one 100 g and the other 200 g are attached via an ideal spring with spring constant k = 0.5 N/m. The system is slid along a frictionless horizontal surface, find the period of oscillation. 2. Relevant equations F=-kx x(t)=Acos(wt - [tex]\phi[/tex]) Fnet=ma Not sure what else. 3. The attempt at a solution I know that after the initial compression/stretch each spring will be displaced by x, and the total displacement will have been 2x. So the equation of motions for the two masses would be: x1(t) = xcos(w1t) x2(t) = xcos(w2t) And I can find the individual angular frequencies w1 and w2, but I don't understand how to go on from here to find the frequency of it as a whole.