JEE Main 2021PhysicsMotion In Two DimensionsMediumMCQ

JEE Main 2021 — Motion In Two Dimensions Question with Solution

JEE Main 2021 (18 Mar Shift 2)

Question

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 : g=10 ms-2, the radius of earth, R=6400×103 m, Take π=3.14)

Choose an option

Show full solutionCorrect option: D
Correct answer
D84 minutes

Step-by-step explanation

For objects to float, 

mg=mω2R

ω= angular velocity of the earth.

R= Radius of earth

ω=gR   ...1

Duration of day =T

T=2πω   ...2

⇒T=2πRg

=2π6400×10310

⇒T60=83.775 minutes

≃84 minutes

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About this question

This is a previous-year question from JEE Main 2021, covering the Motion In Two Dimensions chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.