Two objects attract each other gravitationally with a force of 3.0*10-10N when they are 0.45m apart. Their total mass is 4.0kg. find the individual masses

If everything is in meters and kilograms, then the gravitational force

between 2 masses is

F = G M₁ M₂ / R²

G = 6.67 x 10⁻¹¹

M₁ and M₂ = the masses of the two masses

R = the distance between their centers.

When we plug in 3 x 10⁻¹⁰ for the force, and 0.45 for the distance,

we get the product of the 2 objects M₁M₂ = about 0.911, and

that's as far as we can go without some more information.

The question says that the two masses add up to 4.0 kg.

So now we know that M₁M₂ = about 0.911 and (M₁ + M₂) = 4.0 kg.

With this, we immediately step into a big squishy quadratic equation,

whose solutions are:

one mass = 3.758 kg

the other mass = 0.242 kg.