A man of 80 kg mass is standing on the rim of a circular platform of mass 100 kg rotating about its axis. The mass of the platform with the man on its rotates at 12 r.p.m. If the man moves to the center of the platform, the rotational speed (take platform as a circular ring)

Q. A man is standing on a circular platform which is free to rotate about a fixed vertical axis. If the man starts moving on the periphery of the platform, the COM of the system (man + platform):

Q. A person of $80\text{kg}$ mass is standing on the rim of a circular platform of mass $200\text{kg}$ rotating about its axis at $5$ revolutions per minute (rpm). The person now starts moving towards the centre of the platform. What will be the rotational speed (in rpm) of the platform when the person reaches its centre _____.

Q. A man of mass $m$ is standign at the edge of a large uniform circualr platform of mass $4m$, and radius $R$ which can rotate freely about vertical axis. If the man starts walking over the platform with constant speed $v_0$ relative to platform along the edge, then the angular speed of platform about its axis is

Diagram

Q. A uniform circular platform of mass $120kg$ is rotating in horizontal plane about its own axis at the rate of $12rpm$ with a person of mass $40kg$ on the platform at its edge. If the person gently moves towards centre of platform where his moment of inertia becomes zero then, the angular velocity of platform is:

Q. A man of mass $m$ is standing on a platform of mass $M$ kept on smooth ice. If the man starts moving on the platform with a speed $v$ relative to the platform, with what velocity relative to the ice does the platform recoil ?