The three identical 2-kg spheres are welded to the connecting rods of negligible mass an...

The three identical 2-kg spheres are welded to the connecting rods of negligible mass and are hanging by a cord from point A. The spheres are initially at rest when a horizontal force F = 16 N is applied to the upper sphere. Calculate the initial acceleration of the mass center of the spheres, the rate ? at which the angular velocity is increasing, and the initial acceleration a of the top sphere.