Final answer:
The strength of gravitational force between two objects is determined by their mass and the distance between them, as described by Newton's law of universal gravitation.
Step-by-step explanation:
The factors that determine the strength of gravitational force between two objects are their mass and the distance between them. According to Newton's law of universal gravitation, the gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This is represented by the equation: F = G * (m1 * m2) / r^2 where F is the gravitational force, G is the gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between the centers of the two objects. Choices such as speed and size, density and mass, and mass and temperature do not correctly describe the factors affecting gravitational force as defined by this law. The strength of the gravitational force between two objects depends on their masses and the distance between their centers. This relationship is described by Newton's law of universal gravitation, which states that the force of gravity is directly proportional to the product of the masses of the objects and inversely proportional to the square of the distance between their centers. So, the correct combination of factors is mass and distance.