Question

If diameter is reduced to half from present diameter of earth, its mass becomes 1/8. What is the value of 'g' on earth at this situation?

Answer 1

g(initial)=GM/r²

g(final)=GM/8/(r/2)²

g(final)=4GM/8r²

g(final=GM/2r²=g(initial)/2

Therefore the gravity will become half