Question 12: The angular acceleration of a body, moving along the circumference of a circle, is :
(1) along the tangent to its position
(2) along the axis of rotation
(3) along the radius, away from centre
(4) along the radius towards the centre
Answer: Option (2)
Explanation:
Angular acceleration is defined as the rate of change of angular velocity with respect to time.
For a body moving in a circular path, angular quantities such as angular velocity and angular acceleration are vector quantities.
The direction of angular velocity is given by the right-hand thumb rule
and is always along the axis of rotation, perpendicular to the plane of the circular motion.
Since angular acceleration represents the change in angular velocity,
its direction is the same as that of angular velocity.
Hence, the angular acceleration of a body moving along the circumference of a circle is directed along the axis of rotation.