What will happen to the weight of the body at the south pole, if the earth stops rotating about its polar axis?

Options

A. `1.3 xx 10^(22) N`
B. `8.26 xx 10^(28) N`
C. `1.3 xx 10^(23)N`
D. None of these

Answer

A

Explanation

`omega_(0)= 2pi` rad/day, `omega= 0`
`alpha= (0- 2pi)/(t) = 2pi "rad/day"^(2)= (2pi)/((86400)^(2)) "rad"//s^(2)`
Torque required to stop the earth
`tau= I alpha= FR`
`rArr F= (I alpha)/(R)= ((2)/(5) MR^(2) xx alpha)/(R)= (2)/(5) MR xx alpha`
`= (2)/(5) xx 6 xx 10^(24) xx 6400 xx 10^(3) xx (2pi)/((86400)^(2))`
= `1.3 xx 10^(22) N`