# Circular Motion & Rotational Dynamics

#### 2. Angular Velocity

2. Angular Velocity
It is defined as the rate of change of angular displacement of a body or particle moving in circular path.
(i) It is a vector quantity.
(ii) Its direction is same as that of angular displacement i.e. perpendicular to plane of rotation.
Note : If the particle is revolving in the clockwise direction then the direction of angular velocity is perpendicular to the plane downwards. Whereas in case of anticlockwise direction the direction will be upwards.
(iv) Its dimension is [M0L0T–1]
Types of Angular Velocity :
2.1 Average Angular Velocity :

2.2 Instantaneous Angular velocity :
The instantaneous angular velocity is defined as the angular velocity at some particular instant.
Instantaneous angular velocity

Note: Instantaneous angular velocity can also be called as simply angular velocity.

#### IIT (Class X)

• Unit, Dimension & Error
• Vectors
• Motion in One Dimension
• PROJECTILE MOTION
• NEWTON'S LAWS OF MOTION & FRICTION
• WORK, POWER, ENERGY & CONSERVATION LAWS
• CIRCULAR MOTION & ROTATIONAL DYNAMICS
• GRAVITATION