1. The problem statement, all variables and given/known data Two identical particles of mass M are moving at speeds V/2 in parallel planes in opposite directions. As they approach each other they experience an attractive force with magnitude [tex]F = A/r^5 [/tex] where A is a positive constant and r is the distance between them. Find the scattering angle theta. 2. Relevant equations Here's a diagram I drew: http://img90.imageshack.us/img90/1480/particles.jpg [Broken] 3. The attempt at a solution I know I have to set up some sort of integral, but I don't know how to get started in modelling it. Could someone help me set it up?