JEE Main · 2021 · 18 Mar 2021 · Shift 2 · Gravitation

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If the angular velocity of earth's spin is increased such that the bodies at the equator start floating , the duration of the day would be approximately :
[Take , the radius of earth, , Take ]
  1. (A)1200 minutes
  2. (B)does not change
  3. (C)60 minutes
  4. (D)84 minutes✓ Correct

Answer: (D)

Solution

A body at the equator floats when the ground no longer pushes on it, so gravity alone supplies the centripetal acceleration:

The day then lasts one rotation period,

which is about minutes.

JEE Main · 2021 · 18 Mar 2021 · Shift 2 · Single correct option

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