Physics - Gravitation Question with Solution | TestHub

Weight on the surface of the earth is $W=mg=72$ N.

Acceleration due to gravity at a height $h$ is given by $g_h=g{\left(\frac{R}{R+h}\right)}^2$.

Given $h=\frac{R}{2}$.

Substituting the value of $h$, we get:

$g_h=g{\left(\frac{R}{R+\frac{R}{2}}\right)}^2=g{\left(\frac{R}{\frac{3R}{2}}\right)}^2=g{\left(\frac{2}{3}\right)}^2=\frac{4}{9}g$.

The gravitational force at this height is $W_h=m{g}_h=m\left(\frac{4}{9}g\right)=\frac{4}{9}(mg)$.

Substituting $mg=72$ N:

$W_h=\frac{4}{9}\times 72=32$ N.

Answer: 32 N