One of the ends of the AB rigid rod of mass m and length L = 4R is attached to the edge of the R radius disc with a pin. The other end of the rod can slide freely on the ground without friction. A motor connected to the center of the disk at point O rotates the disk at a constant angular velocity D. At the moment shown in the figure, find all the forces acting on the rod when θ=30degree and the direction OB is vertical.

 

B -L= 4R R 0=30