A nucleus is at rest in the laboratory frame of reference. If it disintegrates into exactly two smal

Question

A nucleus is at rest in the laboratory frame of reference. If it disintegrates into exactly two smaller nuclei, what must be true about the motion of the products?

Professor PC Thomas Classes · Answer

By conservation of linear momentum, the initial momentum is zero. For the final momentum to be zero, the two product nuclei must move in exactly opposite directions.