Gravitational force = G · m₁ · m₂ / r²
' G ' is the 'universal gravitational constant, 6.673 x 10⁻¹¹ m³/kg-s²
m₁ = 60 kg
m₂ = 120 kg
r = 5 m
F = (6.673 x 10⁻¹¹ m³/kg-sec²) · (60 kg) · (120 kg) / (5m)²
F = (6.673 x 10⁻¹¹ · 60 · 120 / 25) · (m³ · kg · kg / kg · s² · m²)
F = 1.922 x 10⁻⁸ (kg · m / s²)
F = 1.922 x 10⁻⁸ Newton (about 0.0000000692 ounce of force)
