Question

Two bodies of equal masses are some distance apart. If $20 \%$ of mass is transferred from the first body to the second body, then the gravitational force between them

• A. incroases by $4 \%$
• B. incroases by $14 \%$
• C. decreases by $4 \%$
• D. decreases by $14 \%$

Answer 1

Answer: (C)

Initially force,
$F_{1}=\frac{G m^{2}}{r^{2}}$
When $20 \%$ mass is transferred from one body to another, then their masses are
$m_{1}=\frac{80}{100} m$ and $m_{2}= \frac{120}{100} m$
So, force is finally
$F_{2}=\frac{G m^{2}}{r^{2}} \times\left(\frac{24}{25}\right)$
Hence, reduction in $F_{2}$ is $\frac{F_{1}-F_{2}}{F_{1}} \times 100 \%=-4 \%$