Question

A 90.0kg person stands 1.25m from a 60.0kg person sitting on a bench nearby. What is the magnitude of the gravitational force between them ?

Answer 1

Answer: $23(10)^{-8} N$

Explanation:

According to Newton's law of Gravitation, the force $F$ exerted between two bodies of masses $m1$ and $m2$  and separated by a distance $r$  is equal to the product of their masses and inversely proportional to the square of the distance:

$F=G\frac{(m1)(m2)}{r^2}$ (1)

Where:

$G=6.674(10)^{-11}\frac{m^{3}}{kgs^{2}}$ is the Gravitational Constant

$m1=90 kg$ is the mass of the first person

$m2=60 kg$ is the mass of the second person

$r=1.25 m$  is the distance between both persons

Solving:

$F=6.674(10)^{-11}\frac{m^{3}}{kgs^{2}}\frac{(90 kg)(60 kg)}{(1.25 m)^2}$ (2)

Finally:

$F=23(10)^{-8} N$  This is the gravitational force between both persons. As you can see is too small.