Conservation of angular momentum of pucks

[dman_PL]

Homework Statement

Two identical pucks, each of inertia m, are connected to a rod of
length 2r and negligible inertia that is free to rotate about its center. A third puck of inertia m strikes one of the connected pucks perpendicular to the rod with a speed vi

Write the expression for conservation of angular momentum in terms of m, vi, the
final velocity of the puck, vf , and ω, the angular speed of the connected pucks. No I’s should be left. You do not need to solve these for vf and ω

Homework Equations

Well angular momentum is L=Iω
I=(1/2)MR^2

The Attempt at a Solution

I have L=((1/2)MR^2)(ω)

However I don't see where the Velocities should go

 

[Andrew Mason]

Homework Statement

Two identical pucks, each of inertia m, are connected to a rod of
length 2r and negligible inertia that is free to rotate about its center. A third puck of inertia m strikes one of the connected pucks perpendicular to the rod with a speed vi

I am not clear about the question. Is there a fixed pivot at the centre of the rod?

AM