Q71 / 90 · JEE Main 2018 (16 Apr Online) · Physics

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

A
weight of the object, everywhere on the earth, will decrease.
B
weight of the object, everywhere on the earth, will increase.
Correct answer
C
except at poles, weight of the object on the earth, will decrease.
D
there will be no change in weight anywhere on the earth.

Solution

Effective acceleration due to gravity,

g^{'} = g - ω^{2} R \cos^{2} ϕ

, where

ϕ

is latitude. There will be no change in gravity at poles as

ϕ = 90^{o}

. At other points as

ω

increases,

g'

will decrease.

Hence, the correct answer is option: 'C'.