Physics · 2020
JEE Main · 3 September 2020, Shift 1 · Q22
A person of 80 kg mass is standing on the rim of a circular platform of mass 200 kg rotating about its axis at 5 revolutions per minute (rpm). The…
A person of $\displaystyle 80$ kg mass is standing on the rim of a circular platform of mass $\displaystyle 200$ kg rotating about its axis at $\displaystyle 5$ 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 \_\_\_\_.
Official answer
9
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JEE Main 2020 Physics question, with the answer from NTA’s final answer key. Where our answers come from.