Suppose that the angular velocity of rotation of earth is increased. Then, as a consequence: (a) Weight of the object, everywhere on the earth, will increase. (b) Weight of the object, everywhere on the earth, will decrease. (c) There will be no change in weight anywhere on the earth. (d) Except at poles, weight of the object on the earth will decrease.

Answer: (d). g' = g - ω² Rcos ²λ; increasing ω increases the reduction wherever cos λ ≠ 0. At the poles cos 90° = 0, so the weight there is unchanged. So the answer is (d): weight decreases everywhere except at the poles.

Suppose that the angular velocity of rotation of earth is increased… | JEE Main 2018 (16 Apr, Shift 1)

Q114JEE Main 2018 · 16 APR · SHIFT 1Easy

Acceleration Due to Gravity

Suppose that the angular velocity of rotation of earth is increased. Then, as a consequence:

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Answer: (d)

$g' = g - \omega^2 R\cos^2\lambda$ ; increasing $\omega$ increases the reduction wherever $\cos\lambda \ne 0$ .
At the poles $\cos 90^\circ = 0$ , so the weight there is unchanged.
So the answer is (d): weight decreases everywhere except at the poles.

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Acceleration Due to Gravity question from JEE Main 2018 (16 Apr, Shift 1)

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