# Homework Help: Two particles moving in a central potential

1. Dec 23, 2017

### Fibo112

1. The problem statement, all variables and given/known data

Two particles move in a central potential. The potential has the form V(r1, r2)=-a/(/r1-r2/^1.5)....
2. Relevant equations

3. The attempt at a solution
I am having trouble understanding what it means for two particles to move in a central potential. From what I understand a central potential is a force field whose force on any given particle points in the direction of a specific point and whose magnitude only depends on the distance r from that point. Does V(r1,r2) mean the sum of the potential energies of the two particles? This doesn't seem to make much sense based on the definition of V(r1,r2).

2. Dec 23, 2017

### TSny

Just to be clear, do the / 's inside the parentheses represent absolute value? Do r1 and r2 represent position vectors?

In this problem, "central force" means that each particle experiences a force from the other particle directed along the line connecting the particles (either attractive or repulsive). The magnitude of the force depends only on the distance of separation $| \vec r_1 -\vec r_2|$

$V(\vec r_1, \vec r_2)$ is the potential energy of the 2-particle system. It is not the sum of two potential energies.