Question

Two persons having mass $50kg$ each, are standing $1m$ apart from each other. Calculate the force of gravitation and also calculate the force of gravity on each. (Take $G=6.67\times {10}^{-11}N{m}^{2}k{g}^{-2}$, mass of earth $M=6\times {19}^{24}kg$, Radius of earth $R=6.4\times {10}^{6}m)$?

Answer 1

$m_1=m_2=50kg,r=1m$
$G=6.67\times {10}^{-11}N{m}^{2}k{g}^{-2}$
Force of gravitation
$F=\frac{G{m}_1{m}_2}{r^2}=\frac{6.67\times {10}^{-11}\times 50\times 50}{(1{)}^2}$
$=1.67\times {10}^{-7}N$
Force of gravity F'$=\frac{GMm}{r^2}$
Here $r=R$ (the radius of earth)
and $m_1=m_2=m$
$F^{|}=\frac{6.67\times {10}^{-11}\times 6\times {10}^{24}\times 50}{(6.4\times {10}^6{)}^2}$
$=0.48\times {10}^{3}N$
$F^{|}$ is much greater than F so the persons will not move towards each other but each of them moves towards the earth.