Why do we use L for angular momentum? Why not M or some other letters?
Because it is secretly called Langular momentum.
That's a good question, I'm sure it's a convention that has it's story.
Well, it's not a letter Newton used.
It's not an abbreviation of the words for 'angular momentum' in French or German.
I've got "Traité de physique" by Biot at home. Maybe I can find it there. (it helped me find out why the magnetic field is 'B')
Perhaps it stands for Leonhard Euler, "the master of us all" whose description of rotational kinematics is still in use today.
In my mechanics book (Theoretical Mechanics, Becker, 1954), J is used as the vector cross product of r and m dr/dt (hence angular momentum), and L is used as dJ/dt (hence torque). Later on, L is used as the Lagrangian L= T - V, and H as the Hamiltonian H = T + V.
I am sorry if this is considered as spam and I shall take the fall for that. This was too good of a joke to forgotten just like that. Great! :rofl:
I think it is just an arbitrary choice that some one made. When I was in school we used h for angular momentum in classical physics. It really makes no difference as long as you define your symbols, which very few people here do.
Separate names with a comma.