With each click on the Action button, what you will see in this display is two spherical objects with masses randomly selected between 0 and 10 kg. Each mass starts at a random location and moves with a constant randomly selected velocity. The line connecting the centers of the objects is displayed in blue and the center of mass is marked with a red X. As the objects move, a track of the movement of the center of mass is laid down by the trail of red Xs. Notice that the center of mass moves in a straight line. What does this tell you about the forces on the two objects? Does it tell you anything about the forces between them?