If two objects have the same mass, the distance between their centers is the primary factor determining the strength of the gravitational force between them.

Here's why:

* Newton's Law of Universal Gravitation: This law states that the force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

* Mathematical Expression: The formula is: F = G * (m1 * m2) / r^2, where:

* F = force of gravity

* G = gravitational constant (a constant value)

* m1 and m2 = masses of the objects

* r = distance between their centers

In simpler terms:

* Closer objects: The closer the objects are, the stronger the gravitational force between them.

* Further objects: The further apart they are, the weaker the gravitational force.

Example:

Imagine two identical balls. If you place them close together, the gravitational force between them will be stronger than if you move them further apart.

Key takeaway: While mass is important for gravity, the distance between objects plays a critical role in determining the strength of the gravitational force.