Universal Gravitation

It states that every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

The gravitational force doubles.

Nothing; mass is not affected by gravitational force.

True.

The gravitational force becomes 4 times bigger.

The formula is $$F = G \frac{{m_1 m_2}}{{r^2}}$$ , where F is the gravitational force, G is the gravitational constant, m1 and m2 are the masses, and r is the distance between the centers of the two masses.

It is a proportionality constant used in the equation of gravitational force, approximately equal to $$6.674 \times 10^{-11} \text{ N(m/kg)}^2$$ .

Gravitational force decreases as the distance between two objects increases, specifically it is inversely proportional to the square of the distance.

Mass is the amount of matter in an object, while weight is the force exerted by gravity on that mass.

The gravitational force increases by a factor of 4.