Moment of inertia about that axis of rotation (AOR) will be zero.

Restitution coefficient e has value 1 for elsatic collision.
In elastic collsion the total energy remains constant.
Restitution coefficient is the ratio of relative speed of separation after collsion to the relative speed of approach before collision.

Note the following notations:
J - angular momentum
K.E.- kinetic energy
I- moment of inertia (MoI)
omega represents angular speed.
1 & 2 are for two cases.(situations)

No impact as no "external" force.

what we need to solve the problem, is value of two masses and their respective acceleration.

What we need to solve the problem is the respective values of velocities alongwith value of mass.
As mass appeares in numerator and denominator so converting it into kg is not required.

All measurements has been done from center of original disc denoted by O.

What we need is net mass and speed of fragments with eqaul mass.

In example PV denoted by r1 and r2 is given for m1 and m2.
