Consider a pointwise particle with mass $m_1$ and speed $v_1$, which collides with a solid $S$ of mass $m_2$, rotational inertia matrix $J$, speed $v_2$, and rotational velocity $\omega_2$. I denote by $r$ the vector between the centrum of inertia of the solid and the collision point, and by $n$ the vector normal to the boundary of the solid at the collision point. The collision is elastic. I think that these data are enough to obtain the velocities and angular momentum of the solid after the collision. The thing is that I'm unable to write down correctly the conservation of momemtum, and to obtain the rigt solution. I was also unable to find a good answer to this on internet... Could you help me please? 

I should probably mention that I'm doing mathematics, and I have not had a physics class for a long time ago...

That might be obvious, but this is in a nonrelativistic context, though the Lorentzian problem also interest me.