The angular momentum of the particle is defined as the moment of momentum about the axis of rotation.
∴ Angular momentum = linear momentum x perpendicular distance from the axis.
If ω is the angular velocity of the particle, then the linear velocity v = r ω.
∴ Angular momentum of each particle = (mv)r = (mrω) r = mr2ω.
∴ Total angular momnetum of the body is L = (Σ mr2ω) = (Σ mr2)
ω = lω where l = Σ mr2.
