Setting up the Lagrangian for a rod with large mass ratio

[danesh]

Hi!
I want to calculate the movement of the rod in the picture, but I don't know how to put up the Lagrangian for the problem.
I have the Shear modulus, $$\mu$$, for the material and M>>m and $$\theta = 0$$. I need the Lagrangian and from there on I think I can manage with the calculations myself.

Thanks

 

[Gamma]

Can you post the wording of the problem.

 

[danesh]

Can you post the wording of the problem.

Well, I have come up with the problem myself.
What I am trying to get is an equation for the motion of the rod, or cantilever if you will. My problem is that I am not sure how to relate the force influencing the heavy block the rod is attached to, to the rod.
I think I need to make a connection between the Shear modulus, or the elasticity modulus of the material the rod and the block is made of to the force which is transferred to the rod.

I will settle for some help using usal mechanics on how the force is transferred from the block to the rod.

Thanks

 

[danesh]

Ok, let me refrase my question a bit.
Can somebody tell me how the rod goes about to "sway" when a impulse is applied on the bigger block with mass M?
If you know a book or a homepage, which you could refer me to for this problem, I would apperciate that as well.