Before entering fully into the meaning of the term angular momentum, we are going to proceed to know the etymological origin of the two words that give it shape:
-Moment, first of all, comes from Latin. Exactly it emanates from the word “momentum”, which can be translated as “impulse”, “movement” or “frequency”.
-Angular, secondly, derives from Greek. In his specific case, from the word “ankulus”, which is synonymous with “bent”.
The idea of angular momentum , which leads us to enter the world of physics and mechanics , refers to a vector magnitude that allows us to refer to the state of rotation of a body . Also called kinetic moment , it can be linked to a rigid solid or a point particle.
In the case of a rigid solid that rotates on an axis, angular momentum is equivalent to the resistance exerted by the body in question against the change in angular velocity (the angle rotated per unit of time). It is important to mention that, under certain conditions, the angular momentum remains constant while the system changes.
The angular momentum of a mass or point particle with respect to a spatial point, meanwhile, is defined as the moment of its momentum taking that point into account. In other words: it is the result of multiplying its position vector by the linear momentum.
To clearly understand what angular momentum is, it can be considered that it allows us to characterize the state of rotation of a point just as linear momentum refers to the state of online translation. Angular momentum, in this framework, is calculated from a position vector and a point particle that has instantaneous velocity (that is, is in motion).
As can be seen, angular momentum is not a magnitude that “belongs” to the body, in the sense that it is not its own. On the contrary, angular momentum will always depend on a reference point taken.
When it comes to carrying out the calculation of the angular momentum of a material point, elements such as the position vector of the body with respect to point O and l, which is the linear movement or momentum of the material point, must be taken into account. body.
Among the angular moments that can be calculated is, for example, that of a satellite that is at a certain distance from the Earth with respect to its center.
It is also necessary to determine that there are two different types of angular momentum: orbital angular momentum and internal angular momentum. To calculate the first, you must take into account the moments of the external forces and also the center. To do the same with the second, both what the O is and those aforementioned external forces must be taken into consideration.
There are many scientists and mathematicians who have studied the topic of angular momentum. However, among the most significant is the German mathematician Emmy Noether.