Why is angular momentum a cross product?

1 Answer

Because it is a vector (pseudo) and being dependent by two other vectors, it will be opportunely represented by a cross product (vectorial product) of the other two vectors.


The angular momentum L = r x p must express a rotational property of the system, then it is necessary that the quantity must have both intensity and directional determination.
But as further definition, angular momentum is a (pseudo)vector because its generation is on a line perpendicular to the plane where the rotation happen.