A body weight \( W \), is projected vertically upwards from earths surface to reach a height above the earth which is equal to nine times the radius of earth. The weight of the body at that height will be:
\( \dfrac{W}{3} \)
\( \dfrac{W}{100} \)
\( \dfrac{W}{91} \)
\( \dfrac{W}{9} \)