How Do You Apply Lagrange Multipliers to a Rolling Disk and Fixed Bar System?

[deniz120]

Homework Statement

Hi all, I need to derive differantial equations of system with lagrange multiplier method, a disk is rolling and a bar is fixed onto the point of a disk

[PLAIN]http://img130.imageshack.us/img130/1669/adsziss.jpg
By deniz120 at 2010-05-31

Homework Equations

The Attempt at a Solution

please check my solution below, I derived T and V for Lagrange, all I need is help for constaints, lagrange multiplier equation. Thanks in advance:)

[PLAIN]http://img263.imageshack.us/img263/3659/tarama0001r.jpg
By deniz120 at 2010-05-31]

 

[vela]

What specifically about the constraint is giving you problems?

You might find this page helpful:

http://www.slimy.com/~steuard/teaching/tutorials/Lagrange.html#CalcVari

 

[deniz120]

unfortunately nothing, I guess there is nonholonomic constraint
thanks

 

[vela]

It's not a nonholonomic constraint.

You have only two coordinates, β and θ. How are they related?

 

[deniz120]

I guess you are right but that is the exact question that I m looking for the answer, how are they related:)

 

[vela]

Really? It's basic geometry. Consider the height of point B.