Question

suppose that the radius of the earth becomes twice of its original radius without any change in its mass.then what will happen to your weight

Answer 1

Our weight will decrease. As
W=m×g
But g= GM/R sq.
As g is inversely proportional to the sq. of the radius, therefore the value of g will reduce and the our weight will decrease.
Hope this helps :)

Answer 2

Weight = mg
= GMm / R²

When radius of earth is doubled
G, M and m are constant
Weight ∝ 1 / R²

∴ If R is doubled weight will be 1/4th of its initial value.