Question

the figure below shows the top view of two balls colliding on a horizontal frictionless table. the path followed by the center of mass of this system is shown by the black vector. which path, labeled a, b, c, or d, will the center of mass follow after the collision? center of mass

Explanation:

According to the law of conservation of momentum, in the absence of external forces (the table is frictionless, so no external horizontal force), the velocity of the center of mass of the system remains constant. Before the collision, the center of mass has a certain velocity (represented by the black vector). After the collision, since there is no external force acting on the system in the horizontal plane, the velocity of the center of mass does not change. So the path of the center of mass should be a straight - line continuation of its initial path. Looking at the options, path B is in the same direction as the initial center - of - mass velocity vector (assuming the black vector is along the general direction related to path B in terms of the coordinate system shown, as the center - of - mass velocity is conserved in the absence of external forces).

Answer:

B. Option Text