Question

What is angular momentum?

Answer 1

Momentum is the product of mass of an object and its velocity. So every moving body posses momentum. The difference between momentum and angular momentum is that, angular momentum deals with rotating or spinning objects.

Angular momentum can be defined as a property of a rotating body which is given by moment of inertia times its angular velocity. (Where moment of inertia is the property by virtue which a body opposes any change in its state of rest or uniform rotation about an axis.) It can be expressed by the equation.   

.

is the Angular momentum

is the Rotational Inertia (moment of Inertia)

is the angular velocity

Angular momentum is also said to be the moment of linear momentum of a body about an axis . Given by,

where is the position vector.

is the linear momentum.

Dimension of angular momentum is

In the absence of external torque angular momentum is a conserved quantity. Some of the useful application of this property is seen in Gyroscope , balancing a cycle ect.