Question

Two particles have a mass of 8kg and 12kg, respectively. if they are 800mm apart, determine the force of gravity acting between them. compare this result with the weight of each particle. g

Answer 1

The magnitude of the force of gravity acting between the particles is:
$F=G\frac{m_1.m_2}{d^2}$ 
The weight of each particle is:
$P=mg$
Now let's plug in the numbers knowing that $G=6.67\times10^{-11}$ , $g=9.81$, $d=0.8$ and m1 and m2 are already given in kilograms. We get then:
$P_1=m_1.g=78.48$N
$P_2=m_2.g=117.72$N
$F=G\frac{m_1.m_2}{d^2}=1.00\times10^{-8}$N

This results shows us why we don't often see objects being attracted to each other, their mass is too small compared to the earth gravitational pull.