Rod is toppling. Find reaction force as a function of theta

[NucEngMajor]

Homework Statement

Rod of length b and mass m topples from vertical position at theta = 0. Calculate the reaction force f as a function of theta. What is the minimal and maximal values of f for theta between 0 and pi

Homework Equations

Third law?[/B]

The Attempt at a Solution

I never really worked a problem such a this in mechanics. So I was shocked to see this on my exam. I would like to know what the solution is. I had no idea how to solve. I suppose this falls under rigid body motion, but all we worked in that topic were lagrangians...

 

[Replusz]

can the rod slip on the ground?

 

[BvU]

I suppose this falls under rigid body motion, but all we worked in that topic were lagrangians...

In general, exam questions are related to the material that's been presented. So you wrote a Lagrangian for this constrained system and found the equation of motion. Did you also learn that the constraint forces follow from the Lagrangian multipliers ?