A 13.8 kg uniform rod is connected to plastic blocks A and B at its ends which move along the horizontal and vertical slots. The rod is initially at rest when 0-20. A spring of constant k= 32 N/m is attached to the rod end at B and the spring is unstretched when 0=0 and its initial length is Ls 0.47 m. A vertical force F = 301 N is pulling block A upward. Using the principle of work and energy determine the angular velocity of the rod at the instant 0-65.9. Note that the rod length is 2.25 m, neglecting friction and the mass of blocks A and B. A G A B