5 $\begingroup$ Imagine a body with moment of inertia, $I$ and with angular velocity $\omega$. If no torque is applied, and moment of inertia is reduced to $I/2$, the angular velocity goes to $2\omega$. Thereby, angular momentum stays conserved. But it is evident that rotational kinetic energy is doubled. So there should be a work done to explain the scenario. I assume, $KE+Work=2KE$. Here no rotational work is being done as there is no torque. So the work must be some translational work done to change moment of inertia. Am I correct? So the rotational kinetic energy is not always conserved in conserved momentum scenario? And is rotational kinetic energy a type mechanical energy? rotational-dynamicsangular-momentumenergy-conservationconservation-lawswork Share Cite Improve this question Follow edited 18 hours ago Qmechanic♦ 213k4848 gold badges593593 silver badges2.3k2.3k bronze badges asked 21 hours ago HimalayanHimalayan 12366 bronze badges $\endgroup$ Add a comment  |