The simple pendulum shown oscillates in the vertical plane (the plane of the figure) as th...

The simple pendulum shown oscillates in the vertical plane (the plane of the figure) as the pendulum cord is being steadily retracted through the opening at O with a constant speed vc. Consider the oscillations of the pendulum between positions and  where θ1 and θ2 are the maximum swing angles of the pendulum at and respectively. Let L1 and L2 denote the lengths of the cord at and respectively, and let m denote the mass of the pendulum bob. Neglecting all forces except gravity and the tension in the cord, determine the angular impulse relative to O provided to the pendulum bob in going from to .

Figure P5.118