Question

plz answer soon as possible

Answer 1

this question is based on principle of gravitation

Answer 2

$force \: \: F= \frac{Gm1m2 }{ {R}^{2} } = \frac{G {m}^{2} }{ {(2R)}^{2} }$
let their density = d
$m1 = m2 = m = \frac{4}{3} \pi {R}^{3} d$
so,
$F = \frac{G}{ {(2R)}^{2} } {( \frac{4}{3}\pi { R }^{3} d) }^{2} = \frac{4G {(\pi d)}^{2} {R}^{4} }{9}$

Hence, F is directly proportional to R^4.