Suppose a 65-kg person stands at the edge of a 9.8-m-diameter merry-go-round turntable that is mounted on frictionless bearings and has a moment of inertia of 1850 kg·m². The turntable is at rest initially, but when the person begins running at a speed of 3.8 m/s (with respect to the turntable) around its edge, the turntable begins to rotate in the opposite direction. Calculate the angular velocity of the turntable.

Under what condition is the angular momentum $L$ of an object conserved?

Based on the conservation of angular momentum ($L=I\mathrm{C9}$), what happens to the angular velocity ($\mathrm{C9}$) of a figure skater when they pull their arms in during a spin, assuming no external torques act on the system?

According to the conservation of angular momentum ($L$), what happens when a spinning ice skater draws in her outstretched arms?

Under which condition is the angular momentum $L$ of a system constant?

According to the conservation of angular momentum, what happens to the rotational speed of a spinning star if its diameter $d$ increases while no external torque acts on it?