A body weights 500 N on the surface of the earth. How much would it weigl half way below the surface of the earth?

Value of acceleration due to gravity decreases on going below the surface of the earth. weight (w) of a body is defined as product of mass ( $m$ ) and acceleration due to gravity ( $g$ ) $w=m g$
The value of $g$ below the surface of earth at a distance $h$ is given by $g^{\prime}=g\left(1-\frac{h}{R}\right)$ $\Rightarrow \quad W^{\prime}=W\left(1-\frac{h}{R}\right)$ Given, $h=\frac{R}{2}, W=500 \mathrm{~N}$ $W^{\prime}=500\left(1-\frac{1}{2}\right)$ $=\frac{500}{2}=250 \mathrm{~N}$