What happens to the acceleration of fragments after a nucleus undergoes fission and one fragment moves away from the other?

When a nucleus undergoes fission, it splits into two or more smaller nuclei, referred to as fragments. Upon splitting, these fragments experience a significant release of energy, propelling them away from each other.

Initially, as the fragments are formed, they are relatively close together and may experience mutual attraction due to residual electromagnetic forces (if they are charged) or even nuclear forces. As the fragments separate, the distances between them increase. According to Newton's laws of motion, particularly the inverse square law, the force between two charged objects decreases as the distance between them increases. Therefore, as the fragments move further apart, the net force acting on each fragment decreases.

Since acceleration is directly proportional to force (as per Newton's second law, F = ma), if the force acting on a fragment decreases as the fragments move away from each other, the acceleration of those fragments must also decrease. This relationship explains why, in this scenario, the acceleration of the fragments decreases as they continue to separate in the aftermath of the fission event.