In the figure shown, the instantaneous speed of end I of the rod is v to the left. The angular velocity of the rod of length L must be

The velocities of the ends A and B along the length of rod should be the same. Hence, vAcos⁡30∘=vBcos⁡30∘⇒vA=vB=vHence, the angular velocity of the rod isω=vAB⊥l=2vsin⁡30∘l⇒ω=vl