HW$05\mathrm{.}3-$ Textbook Problem $17\mathrm{.}123$

A slender rod AB with mass $\backslash ($ m $\backslash )$ and length $\backslash ($ L $\backslash )$ is released from rest in the position shown. It swings down to a vertical position and strikes a second and identical rod CD that is resting on a frictionless surface. Assuming that the coefficient of restitution between the rods is $\backslash (\backslash$varepsilon$=0\mathrm{.}4\backslash ),$ determine the velocity of $\backslash (\backslash$operatorname$\{$rod$\}$ C D $\backslash )$ immediately after the impact.

Figure $60$: Problem $17\mathrm{.}123.$