The open-link chain of length $L$ and mass $\rho$ per unit length is released from rest in the position shown, where the bottom link is almost touching the platform and the horizontal section is supported on a smooth surface. Friction at the corner guide is negligible. Determine
(a) the velocity $v_{1}$ of end $A$ as it reaches the corner and ( $b$ ) its velocity $v_{2}$ as it strikes the platform.
(c) Also specify the total loss $Q$ of energy.