Question

Two point masses each equal to $1$ kg attract one another with force of ${10}^{-10}N$. The distance between the two point masses is $(G=6.6\times {10}^{-11}MKS$ units$)$

• A. $8cm$
• B. $0.8cm$
• C. $80cm$
• D. $0.08cm$

Answer 1

The correct option is C $80cm$

According to newton's Gravitational Law
$F_g=\frac{G{M}_1{M}_2}{r^2}$ here $F_g={10}^{-10}$ Newton,
$m_1=m_2=1$kg,
$G=6.6\times {10}^{-11}$
So $r^2=\frac{G{M}_1{M}_2}{F_g}=\frac{6.6\times {10}^{-11}\times 1\times 1}{{10}^{-10}}=0.66$
or $r=0.8125$ metre $=81.25cm=80cm$