angular momentum Symbol L or J. SI unit kilogram meter square per second (kg.m2/s). The angular momentum L of a particle referred to an arbitrary fixed point (fixed in the inertial reference frame) as origin is defined as the vector product of radius vector and the momentum of the particle. see fig
L= r ´ p = r ´ Mv
The magnitude of L is
L = r p sin q
where q is the smaller angle between r and p . L is normal to the plane containing r and p. Its direction is obtained by the right hand screw rule, i.e. if one rotates the right hand screw from r to p through the smaller angle between them the direction of the linear motion of the screw gives the direction of L.
The angular momentum for a system of particles can be obtained by vector addition of the angular momentum of all the particles.
If a rigid body is rotating with angular velocity w , about any fixed axis, its angular momentum can be found by multiplying moment of inertia*, I of the body about the axis and the angular velocity.
L = I w
