How Fast Can a Trebuchet Fling a Light Object?

[KvnBushi]

Homework Statement

A war-wolf, or trebuchet, is a device used during the Middle Ages to throw rocks at castles and now sometimes used to fling pumpkins and pianos. A simple trebuchet is shown in Figure P8.77. Model it as a stiff rod of negligible mass 3.00 m long and joining particles of mass 60.0 kg and 0.120 kg at its ends. It can turn on a frictionless horizontal axle perpendicular to the rod and 14.0 cm from the particle of larger mass. The rod is released from rest in a horizontal orientation. Find the maximum speed that the object of smaller mass attains.
Pic: www.s-consolidated.com/graphics/trebuchet.jpg[/URL]

[h2]Homework Equations[/h2]
$$K = \frac{1}{2} I_{cm} w^2 + \frac{1}{2} M v_{cm}^2$$


[h2]The Attempt at a Solution[/h2]

I am not even sure how to model it yet. I will attempt some things and write them as I go.

 

[member 553083]

I_{cm} = (M + m) * l^2/12where M is the 60kg, m is the 0.12kg and l is 3mI_{cm} = 20.25 kg*m^2v_{cm} = (M + m)*v/(M + m)v_{cm} = vK = \frac{1}{2} I_{cm} w^2 + \frac{1}{2} M v_{cm}^2 K = \frac{1}{2} * 20.25 * w^2 + \frac{1}{2} * 60 * v^2I am not sure where to go from here.