The two variables that affect the gravitational force between objects are:
1) Mass: The mass of the objects involved is a crucial variable that affects gravitational force. As the mass of objects increases, the gravitational force between them also increases. The force of gravity is directly proportional to the mass of the objects. For example, if the mass of both objects doubles, the gravitational force between them also doubles.
2) Distance: The distance between the objects is another variable that affects gravitational force. The force of gravity is inversely proportional to the square of the distance between the objects. In other words, as the distance between the objects increases, the gravitational force decreases. For example, if the distance doubles, the gravitational force becomes one-fourth of its original value.