Question

The gravitational force acting on a particle of $1g$ due to a similar particle is equal to $6.67\times {10}^{-11}$. Calculate the seperation between the particles.

Answer 1

Given,

$M_1=M_2={10}^{-3}kg,G=6.67\times {10}^{-11}$

So, $F=\frac{G{M}_1{M}_2}{r^2}$

Where r is the distance between them,

$F=\frac{6.67\times {10}^{-11}\times {10}^{-3}\times {10}^{-3}}{r^2}$

$6.67\times {10}^{-11}={\frac{6.67\times {10}^{-11}\times {10}^{-6}}{r}}^2={10}^{-6}\Rightarrow r=\sqrt{{10}^{-6}}={10}^{-3}=1mm$