Question

Arrange the following pairs of masses in the decreasing order of the gravitational attraction between them.

• A. $CaseIV$: $m_1=2kg$, $m_2=6kg$, $d=2m$
• B. $CaseII$: $m_1=2kg$, $m_2=4kg$, $d=2m$
• C. $CaseI$: $m_1=1kg$, $m_2=1kg$, $d=1m$
• D. $CaseIII$: $m_1=2kg$, $m_2=1kg$, $d=2m$

Answer 1

According to Universal law of gravitation, the gravitational force is directly proportional to the product of the masses of the objects and inversaly proportional to the square of the distance between them.
$F\propto \frac{m_1{m}_2}{d^2}$
$CaseI:F_1\propto \frac{1\times 1}{1^2}=1$
$CaseII:F_2\propto \frac{2\times 4}{2^2}=2$
$CaseIII:F_3\propto \frac{2\times 1}{2^2}=0.5$
$CaseIV:F_4\propto \frac{2\times 6}{2^2}=3$