# Homework Help: Scattering of two charged particles

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1. Aug 3, 2016

### Dazed&Confused

1. The problem statement, all variables and given/known data
Two identical charged particles, each of mass $m$ and charge $e$, are intitialy far apart. One of the particles is at rest at the origin, and the other approaching it with velocity $v$ along the line $x=b, y=0$ where $b=e^2/2 \pi \epsilon_0 mv^2$. 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 $x=b, y=0$ a line threw me off. I'm not sure what they mean by that.

2. Aug 3, 2016

### TSny

I'm not sure either. Maybe they mean that the particle is initially traveling in the x-z plane along a line that is parallel to the z axis at x = b.

3. Aug 3, 2016

### Dazed&Confused

That does make sense, although why introduce a third dimension if the particles are in a plane? Anyway I'll try it with what you say.

4. Aug 3, 2016

### TSny

Good point.

The important thing is that the projectile particle is initially moving along a straight line with impact parameter b. I think that's all you really need to know.