1. The problem statement, all variables and given/known data Two identical charged particles, each of mass [itex]m[/itex] and charge [itex]e[/itex], are intitialy far apart. One of the particles is at rest at the origin, and the other approaching it with velocity [itex]v[/itex] along the line [itex]x=b, y=0[/itex] where [itex] b=e^2/2 \pi \epsilon_0 mv^2[/itex]. Find the scattering angle in the CM frame, and the directions in which the two particles emerge in the Lab. It then quotes a relevant section which was on Rutherford Scattering 2. Relevant equations 3. The attempt at a solution Calling [itex]x=b, y=0[/itex] a line threw me off. I'm not sure what they mean by that.