If the gravitational force between objects of equal mass is 5.0*10^-9 N when the object are 12 m a part. What is the mass of each object?

The gravitational force is

F = G (one mass) (the other mass) / (distance between them) ²

G = the universal gravitational constant

= 6.67 x 10⁻¹¹ newton-meter²/kg²

If the masses are equal, then F = G m²/R²

Divide each side by 'G': F/G = m²/R²

Multiply each side by R² : m² = F R² / G

Take the square root of each side: m = √ (FR²/G)

Mass = √ (5 x 10⁻⁹ x 144 / 6.67 x 10⁻¹¹)

= √ (500 x 144 / 6.67)

= 103.9 kilogram (rounded)