Question 396080
It should be


{{{f = k(m[1]*m[2])/d^2}}} (the force is dependent on the product, not the sum). If m_1 and m_2 are each divided by 2, and the distance is tripled, then


{{{f[2] = k((1/4)m[1]*m[2])/(3d)^2 = (1/36)f}}}, so the force caused by gravity is 1/36 as much.


In case you're interested, the gravitational constant is approximately {{{6.67*10^(-11)}}} Nm^2/kg^2.