Question

R

Answer 1

Answer:

$4.5\ \text{N}$

Explanation:

$F_1$ = Gravitational force between the objects = $18\ \text{N}$

$r_1$ = Initial distance between the two objects

$r_2$ = Final distance between the two objects = $2r_1$

Gravitational force between two objects is given by

$F=\dfrac{Gm_1m_2}{r^2}$

So

$F\propto \dfrac{1}{r^2}$

$\dfrac{F_2}{F_1}=\dfrac{r_1^2}{r_2^2}\\\Rightarrow \dfrac{F_2}{F_1}=\dfrac{r_1^2}{(2r_1)^2}\\\Rightarrow \dfrac{F_2}{F_1}=\dfrac{1}{4}\\\Rightarrow F_2=\dfrac{F_1}{4}\\\Rightarrow F_2=\dfrac{18}{4}\\\Rightarrow F_2=4.5\ \text{N}$

The new force of attraction between the objects is $4.5\ \text{N}$.