1. The problem statement, all variables and given/known data A spring of constant k connects two masses, m1 and m2. The system is constrained to longitudinal oscillations (in the direction of the line connecting the masses). (a) Find the equivalent 1D problem and solve the equations of motion. (b) Use the solution to the previous point to obtain the solution of the original problem. 2. Relevant equations I solved point a. I got that the lagrangian is :(0.5*m1*v1^2)+0.5*m2*v2^2)-0.5*k*(x1+x2-lo) Is that correct? And the solution of the NDE are without cos,sin because x1''=-k/m1 for example. was I wrong? Now for point b, I should you coordinate x1,y1,x2,y2? beacause the masses can also go up and down during their motion? How will the lagrangian will look like? Please help me.