AIIMS2004PhysicsGravitation
Assertion : There are very small sporadic changes in the period of rotation of the earth. Reason : Shifting of large air masses in the earth's atmosphere produce a change in the moment of inertia of the earth causing its period of rotation to change.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion
- BIf both assertion and reason are true but reason is not the correct explanation of assertion
- CIf assertion is true but reason is false
- DIf both assertion and reason are false.
Correct answer
A. If both assertion and reason are true and reason is the correct explanation of assertion
Step-by-step solution
Normally when a body is moving in a straight line, whatever be the internal changes, the centre of mass continuous in its trajectory with the same velocity and a system that is rotating continues to rotate with the same angular velocity and changes occur in such a way that the angular momentum is conserved. Classical physics, taking the whole of the earth as a system does not allow sporadic changes in the speed of the earth. However, according to the information on the earth's rotation by U.S. Naval observatory spo