### Rotational Motion About A Fixed Axis Angular Momentum System Of Particles And Rotational Motion

**Concepts in Rotational Motion**

**- Moment of Inertia:**

- Remember it as the rotational equivalent of mass. It measures an object’s resistance to angular acceleration.

**- Angular Momentum:**

- Think of it as the rotational equivalent of linear momentum. It describes the quantity of rotational motion in an object.

**- Relation between Torque and Angular Momentum:**

- Torque is the rate of change of angular momentum, just as force is the rate of change of linear momentum.

**- Conservation of Angular Momentum:**

- This principle states that the total angular momentum of a closed system remains constant unless acted upon by an external torque. Imagine a spinning ice skater pulling their arms in or out to increase or decrease their rotational speed, conserving the total angular momentum.

**- Moment of Inertia of a System of Particles:**

- Visualize it as the sum of the moments of inertia of each particle in the system, weighted by their respective distances from the axis of rotation.

**- Parallel Axis Theorem:**

- This theorem provides a convenient method for calculating the moment of inertia of an object about an axis parallel to its center of mass.

**- Perpendicular Axis Theorem:**

- This theorem helps calculate the moment of inertia of an object about an axis perpendicular to two other perpendicular axes.

**- Kinetic Energy of Rotation:**

- Imagine a spinning object; its kinetic energy is dependent on its moment of inertia and angular velocity.

**- Work-Energy Theorem for Rotation:**

- Just as work done on a linear object changes its kinetic energy, work done on a rotating object changes its rotational kinetic energy.

**- Rolling Motion:**

- Rolling Motion comprises rotation and translation. Think of a wheel rolling down a hill, rotating about its axis while moving translationally.