The uniform slender rod of length l is welded to the bracket at A on the underside

Question:

The uniform slender rod of length l is welded to the bracket at A on the underside of the disk B. The disk rotates about a vertical axis with a constant angular velocity w. Determine the value of w which will result in a zero moment supported by the weld at A for the position θ = 60° with b = l/4.