The weight of a body at the surface of earth is 18   N . The weight of the body at an altitude of 3200…

As height of the object is considerable compared to the radius of the earth, therefore approximation formula can not be used.

So weight at given height,

$F=m{g}^{\text{'}}=\frac{GMm}{{\left(R+\frac{R}{2}\right)}^2}=\frac{4}{9}\frac{GMm}{R^2}$

$\Rightarrow m{g}^{\text{'}}=\frac{4}{9}\left(mg\right)$

$=\frac{4}{9}\times 18$

$=8 \mathrm{N}$