Consider a point-mass moving around a fixed point on a circle with radius $r$ with constant angular velocity $\omega$. At a certain moment of time, the connection is removed, and the point-mass flies away tangentially to the circle.
I need to describe this motion in the inertial frame (where the point-mass is rotating in the beginning) and in a reference frame rotating with angular velocity $\omega$ around the fixed point (where the point-mass is at rest in the beginning). How can I do that?