Question

A particle is suspended from a spring and it stretches the spring by 1 cm on the surface of earth the same particle will stretches the same spring at a place 800 km above earth surface by

Answer 1

g, at the surface of the earth = GM/R2 ------------(1)

and lets take g', at some distance R' from the centre of the earth: g' = GM/R'2 -----------(2)

Now g' = 1% less than the previous value ie g' = 99g/100

Now (2) becomes,

99g/100 = GM/R'2 ---------------(3)

Dividing the equation (1) & (3) and solving it further by putting the given value of R ie radius of the earth, we get

R' = 6432.24 km

which means distance of the place from the surface of the earth is: 32.24 ≈ 30 KM ABOVE THE EARTH 'S SURFACE

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