Question

The angular velocity of a planet revolving in an elliptical orbit around the sun increases, when it comes closer to the sun. This is due to ______________

(a) Conservation of momentum

(b) Newton’s second law of motion

(c) Conservation of angular momentum

(d) Law of angular velocity

I got this question during an online exam.

This is a very interesting question from Significance of Rotational Motion in chapter System of Particles and Rotational Motion of Engineering Physics I

Answer 1

Correct choice is (c) Conservation of angular momentum

Best explanation: The angular velocity of a planet revolving in an elliptic orbit around the sun increases when it comes closer to the sun increases when it comes closer to the sun because its moment of inertia about the axis through the sun decreases. When it goes far away from the sun, its moment of inertia decreases so as to conserve angular momentum.