The moment of linear momentum is called angular momentum.
It is denoted by L.
Angular momentum, L = I ω = mvr
In vector form, L = I ω = r x mv
Its unit is ‘joule-second’ and its dimensional formula is [ML2T-1].
Torque, τ = dL / dt
Conservation of Angular Momentum
If the external torque acting on a system is zero, then its angular momentum remains conserved.
If τ ext. 0, then L = I (ω) = constant ⇒ I1 ω1 = I2 ω2
Angular Impulse
Total effect of a torque applied on a rotating body in a given time is called angular impulse. Angular impulse is equal to total change in angular momentum of the system in given time. Thus, angular impulse