If torque is applied to an object, it begins to rotate.
1) During rotation, every particle moves in a circle about the axis of rotation. Do these particles accelerate while executing this circular motion after torque is applied to it? In the derivation of the rotational kinetic energy and the moment of inertia of a rotating rigid body, we consider particles not accelerating but each moving with different velocities. But for Torque, a force has to be applied... and so shouldn't this force cause an acceleration(linear) of the particles?
2) My second question is completely unrelated to this-
Consider a thin (uniform) rod rotating about an axis passing through its end and perpendicular to its length. Does the rod rotate about its centre of mass or about the axis of rotation?
A similar question had been asked and this is part of the answer: " A pure torque any point on the body (with no net force) will purely rotate a rigid body about its center of mass."
Since a torque has to be applied to cause rotational motion, why not say that the rod rotates about the axis of rotation? Why the COM of the rod?
3)My third question is that if the rotation is about the COM, does the COM remain stationary/ move with a constant velocity?