Definition: The degree to which a body rotates, gives its angular momentum. It is defined as the product of the moment of inertia “I” and the angular velocity “ω”
Angular momentum in terms of Linear momentum can be written as
r = length vector
p = linear momentum
The unit for Angular momentum is given as kilogram meter square per second (kg m2/s). Angular Momentum formula is made use of in computing the angular momentum of the particle and also to find the parameters associated to it.
Angular Momentum Numericals
Problem 1: A solid cylinder of mass 200 kg rotates about its axis with an angular speed of 100ms-1. If the radius of the cylinder is 0.5 m. Compute the angular momentum of the cylinder about its axis?
Given: Mass M = 200 kg,
Angular speed ω = 100 ms-1,
Radius r = 0.5 m,
Since it is a solid cylinder, Moment of Inertia I
I= 25 kg m2
The angular momentum is given by L =
L = 25 x 100
= 2500 kg m2/s
Problem 2: Compute the angular momentum of the rod of radius 1 m and mass 2 kg spinning with velocity 5 rad/s?
Given: Radius r = 1 m,
Mass M = 2 kg,
Angular Velocity ω = 5 rad/s
The angular momentum is given as L = I ω
L = 5 kg m2 s-1.