# Define Angular Acceleration

## Online Tutoring Is The Easiest, Most Cost-Effective Way For Students To Get The Help They Need Whenever They Need It.

Angular acceleration is defined as the rate of change of angular velocity with respect to time. Angular acceleration represented as ‘α’ is a vector quantity and therefore has both magnitude and direction. When an object moves in a circular path, unlike linear motion where it travels in a straight line path, in circular motion it constantly changes its direction and path to follow the circular curve and this change in angular velocity produces angular acceleration.

Example 1: The angular velocity of an object travelling in a circular path is changing at a rate 40rad/sec. What is the angular acceleration of the object in the time period of 8 seconds?

The formula: Angular acceleration, α = ?ω/?t

Here, ?ω = change in angular velocity = 40rad/sec

?t= time interval = 8 seconds

This gives: Angular acceleration, α = (40rad/sec)/ (8secs)

Hence the angular acceleration of the given object, α = 5 rad/sec2

Example 2: If the instantaneous angular acceleration of an object travelling with an angular
velocity of 21rad/sec is 3rad/sec2, then what is the time at that particular instant?

The formula: Instantaneous Angular acceleration, α = dω/ dt

Given instantaneous angular acceleration, α = 3rad/sec2

dω = angular velocity at the particular instant = 21rad/sec

dt= time at that instant

This gives: 3 = (21rad/sec)/ (time) ==> time = 21/3 = 7secs.

Hence the time at the particular instant, t = 7 seconds.

 More Sub Topics Mirror Formula What is the formula for velocity Wave Motion Fluid Dynamics Titration Curves View All Sub topics