A disc is rotating with angular velocity `omega`. If a child sits on it, what is conserved?

As disc is rotating with angular speed omega . If a child sits on it, what is conserved?

When a disc is rotating with angular velocity omega , a particle situated at a distance of 4 cm just begins to slip . If the angular velocity is doubled , at what distance will the particle start to slip ?

When a disc is rotating with angular velocity omega , a particle situated at a distance of 4 cm just begins to slip . If the angular velocity is doubled , at what distance will the particle start to slip ?

Two discs of radii R and 2R are pressed against each other. Initially, disc with radius R is rotating with angular velocity omega and other disc is stationary. Both discs are hinged at their respective centres and are free to rotate about them. Moment of inertia of smaller disc is I and of bigger disc is 2I about their respective axis of rotation. Find the angular velocity of bigger disc after long time.

Two discs of radii R and 2R are pressed against eachother. Initially, disc wit radius R is rotating with angular velocity omega and other disc is stationary. Both discs are hinged at their respective centres and are free to rotate about them. Moment of inertiaof smaller disc is I and of bigger disc is 2I about their respective axis of rotation. Find the angular velocity of bigger disc after long time.