Final answer:
The magnitude of the gravitational force is proportional to both the mass of the object and its distance from the center of the Earth, according to Newton's universal law of gravitation.
Step-by-step explanation:
The magnitude of the gravitational force acting on an object is proportional to both its mass and the distance from the center of the Earth. This principle is encapsulated in Newton's universal law of gravitation, which states that every particle in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. The formula for calculating this force is F = G (m1*m2)/r², 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.