Answer to Question #109862 in Physics for Daniel

Question

At what distance apart would two equal masses of 150 kg need to be placed for the force between them to be 2.0
x 10^-5 N?

Answer 1

The Newton's gravity law says

$F=G\frac{m_1m_2}{r^2}.$

Hence, the distance between masses

$r=\sqrt{\frac{Gm^2}{F}}=\sqrt{\frac{6.67\times 10^{-11}\times (150)^2}{2.0\times 10^{-5}}}=0.27\:\rm m.$