Finding Velocity and Pressure of Half-Sphere on Horizontal Plane

[Nea]

Homework Statement

The half a sphere with a 'm' mass and 'r' radius is equilibrated on a plan absolutely polished horizontal with the side of the AB wire. So the surface of the half a sphere has with the horizontal plan an alpha angle. Find, after the break of the wire, the velocity of the O center and her maximal value too, also the maximal value of the pressure of the half-sphere over the horizontal. Find that for small angles it behaves like a mathematical pendulum.
Illustration:
http://img135.imageshack.us/img135/9526/fiz1rf6.th.jpg

Homework Equations

The Attempt at a Solution

I think that the lagrange's equations can be employed to solve it.

 

[Dox]

Hello.

I think that using Lagrange's methods won't help you. The best you can do is using Newton... use vectors!

Regards.

 

[esalihm]

I would use Newton as well but I think it will take some work to draw the components and figure out which contributes to the torque in which way