Answer:
[tex]4.5\times 10^{-10}\ N[/tex]
Explanation:
The gravitational force between two masses is inversely proportional to the square of the distance between them such that,
[tex]\dfrac{F_1}{F_2}=\dfrac{r_2^2}{r_1^2}[/tex] .....(1)
We have,
r₁ = 208 m, [tex]F_1=1.8\times 10^{-9}\ N[/tex], r₂ = 416 m, F₂ = ?
Put all the values in relation (1) such that,
[tex]F_2=\dfrac{F_1r_1^2}{r_2^2}\\\\F_2=\dfrac{1.8\times 10^{-9}\times 208^2}{416^2}\\\\F_2=4.5\times 10^{-10}\ N[/tex]
So, the required force is [tex]4.5\times 10^{-10}\ N[/tex]. Hence, the correct option is (d).