(Solved): The bridge girder \( G \) of a bascule bridge is raised and lowered using the drive mechanism shown ...

The bridge girder \( G \) of a bascule bridge is raised and lowered using the drive mechanism shown. If the hydraulic cylinder \( A B \) shortens at a constant rate of \( 0.15 \mathrm{~m} / \mathrm{s} \), determine the angular velocity of the bridge girder at the instant \( \theta=60^{\circ} \). Ans. \( w=0.0808 \mathrm{rad} / \mathrm{s} \)