Finding Forces Exerted at A and B on Rod AB

[roldy]

Homework Statement

The 2 kg rod AB and the 3kg rod BC are connected as shown to a disk that is made to rotate in a vertical plane at a constant angular velocity of 6 rad/s clockwise. For the position shown, determine the forces exerted at A and B on rod AB.

Homework Equations

summation of forces
mass moment of inertia
relative velocites and accelerations

The Attempt at a Solution

I think I solved the accelerations and angular accelerations correctly but at this point I'm unclear as to what to do next.
http://img217.imageshack.us/my.php?image=130oc0.jpg

 

[Gokul43201]

Looks good so far!

You accidentally set the wrong component to zero in the line for a_A, but you fixed it in the next line. Make sure you correct that line too!

Now that you have a_A and a_B, throw away everything except rod AB. You can now describe the dynamics of rod AB in terms of a center of mass acceleration (=(a_A+a_B)/2) and an angular acceleration about the center (=(a_A-a_B)/L). This can be seen as coming from a pure force (acting at the center) and a pure couple (torque about the center). From here, finding the forces at A and B is just a matter of adding and subtracting.