Particles A and B, which are connected via a massless linear spring, have been thrown up i...

Particles A and B, which are connected via a massless linear spring, have been thrown up in the air and are moving under the action of the spring force and their own weight. Assuming that no other forces are affecting the motion of the particles, what will be the acceleration of their center of mass?

Note:Concept problems are about explanations, not computations.

Figure P3.86