JEE Main 2017 — Gravitation Question with Solution
From: JEE Main 2017 (Online) 8th April Morning Slot
Question
If the Earth has no rotational motion, the weight of a person on the equator is W. Determine the speed with which the earth would have to rotate about its axis so that the person at the equator will weigh W. Radius of the Earth is 6400 km and g=10 m/s2.
Choose an option
Show full solutionCorrect option: C
Correct answer
C0.63 10−3 rad/s
Step-by-step explanation
Initially when earth is not rotating then weight of the person is .
When earth rotares about it's axis then weight =
Then,
g' = g 2R cos2
= g 2R cos2 0o
2R =
=
= 0.63 103 rad/s
When earth rotares about it's axis then weight =
Then,
g' = g 2R cos2
= g 2R cos2 0o
2R =
=
= 0.63 103 rad/s
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