An ore-lifting cage of mass 600kg is lowered from the surface of a mine shaft to the bottom, which is 800m below ground level.
(i) Calculate the weight of the cage when it is at the surface.
(ii) Determine its weight when it is stationed at the bottom of the shaft, assuming Earth to be of uniform density.
(iii) Find the percentage decrease in the weight.
Take g=9.80ms−2 at the surface and RE=6.4×106m.