A body stretches a spring by a particular length at the earth's surface at equator. At what height above the south pole wil ilt stretch the same pering by the same length ? Assume the earth to be spherical.

Answer

A

Explanation

At equator `g'=g-omega^2R`
Let at h height above sout pole , the acceleration due to gravity is same.
`then here g'=g(1-(2h)/R)`
`:. G-omega^2r=g(1-((2h)/R))`
`or 1-(omega^2R)/(2g)=1-(2h)/R`
or `h=(omega^2R^2)/(2g)`
(7.3xx10^-)^2xx(6400xx10^-3)^2)/(2xx9.81)`
`=((7.3)^2xx(64)^2)/16.62`
`=11125m=10km(approx)`