### Chapters

## Angular Momentum
The rotational analogue of linear momentum is Physics. For the test, you will probably have to deal only with the angular momentum of a particle or body moving in a circular trajectory. In such a case, we can define angular momentum in terms of moment of inertia and angular velocity, just as we can define linear momentum in terms of mass and velocity: L = l? The angular momentum vector always points in the same direction as the angular velocity vector. ## Angular Momentum of a Single Particle
Let’s take the example of a tetherball of mass
The tetherball has a moment of inertia of
This is the value we would expect from the cross product definition we saw
earlier of angular momentum. The momentum, mof a particle moving in
a circle is always tangent to the circle and perpendicular to the radius.
Therefore, when a particle is moving in a circle,v L = pr sin90° = pr = mvr ## Newton’s Second Law and Conservation of Angular MomentumIn the previous chapter, we saw that the net force acting on an object is equal to the rate of change of the object’s momentum with time. Similarly, the net torque acting on an object is equal to the rate of change of the object’s angular momentum with time:
If the net torque action on a rigid body is zero, then the angular momentum of
the body is constant or conserved. The ## Example
Given the context, the answer to this question is no secret: it’s
As Brian spins on the ice, the net torque acting on him is zero, so angular
momentum is conserved. That means that |

- Home
- Universities
- Colleges
- Schools
- Results and Date Sheets
- Test Prep Books
- Lucrative Jobs
- General Tests
- Subject Tests
- Subject Refreshers
- Test Preparation
- Lessons and Practice
- CSS Exam
- Articles
- Career Channel
- Scholarships
- General Interest