Question

Predict the gravitational force between two 15-kg balls whose centers are 35 m apart.

Answer 1

`F=G(m_1-m_2)/(r^2)`

`=((6.67*10^(-11)N*m/kg^2)(15kg) )/((0.35m)^2)`

`=1.2*10^(-7) N`

Because the weight of one ball is mg = 147 N, the gravitational force between the two balls is
`1.2*10^(-7)N` or
`8.4*10^3` parts per billion of the weight.