nope...itz not necessary that the frame should be inertial....the only necesarry condition is that the TOTAL EXTERNAL TORQUE acting ABOUT THE REFERENCE AXIS should be ZERO...
An inertial frame of reference (FOR) is a non-accelerating FOR , for example if a person is observing a moving car while at rest or while moving at constant velocity, he is in an inertial FOR. A...
More or less. There is a law of conservation of angular momentum, according to which Earth can't gain or lose angular momentum on its own - if for example it loses angular momentum, it has to go...