Wave Mechanics Problem Double Pendulum and a Spring

[kk27]

I'm in a wave mechanics class and a homework assignment asks us to describe what would happen if a driving force is applied to m1, m2, or both. The explanation should be both calculational and written. I have no idea how to model this system in equation form! Help!

 

[aim1732]

Although you could analyse the situation using the equations of dynamics a simpler way is to write the net energy of the system at a general point in its path(which would include kinetic and potential energies) and differentiate the function and then put it equal to zero since the energy of the system remains constant.That should tell you the relation b/w a and x.
Note-If a force continuously acts on the system the net energy content of the system is not constant since you have work energy coming into the system.