Rotating Bar Problem: Solving Angular Velocity

[Mugged]

Ok so I am given a rigid bar, with length L. There is a point P right at the bottom of the bar which is moved at a constant speed V along the floor. The bar rests on a step of height L/2. I have to determine the rate of change of theta with respect to theta (angular velocity with respect to theta). This would only apply for theta bigger than 30 degrees and less than 90 degrees because the bar would otherwise be vertical or fallen off the step. C is the center of the bar.

Picture:
[PLAIN]http://img836.imageshack.us/img836/5905/problems.png

I have no idea where to start, can anyone help?

 

[Doc Al]

Hint: Find the relationship between the angle and the distance of point P from the step.

 

[Mugged]

ah hang on, made a mistake

 

[Mugged]

op i got it, thank you so much doc al. I don't understand why i didnt think of that in the first place...my immediate idea was to start using formulas for two body problems -.-