Angular momentum
![This gyroscope remains upright while spinning due to the conservation of its angular momentum.](/Images/godic/202501/28/Gyroskop0911.jpg")
![Velocity of the particle m with respect to the origin O can be resolved into components parallel to (v//) and perpendicular to (v⊥) the radius vector r. The angular momentum of m is proportional to the perpendicular component v⊥ of the velocity, or equivalently, to the perpendicular distance r⊥ from the origin.](/Images/godic/202501/28/Ang_mom_2d0911.png")
![](/Images/godic/202501/28/Torque_animation0911.gif")
![Moment of inertia (shown here), and therefore angular momentum, is different for every possible configuration of mass and axis of rotation.](/Images/godic/202501/28/Moment_of_inertia_examples0912.gif")
In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational analog of linear momentum. It is an important quantity in physics because it is a conserved quantity – the angular momentum of a system remains constant unless acted on by an external torque.