Final answer:
The gravitational force between two objects of masses m and 2m is equal in magnitude, regardless of their different masses, due to Newton's third law.
Step-by-step explanation:
The question pertains to the gravitational force between two objects with masses m and 2m that are separated by a distance r. According to Newton's universal law of gravitation, the force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers of mass.
Using Newton's third law, which states that forces between two bodies are equal in magnitude and opposite in direction, it can be concluded that the magnitude of the force that the object with mass m exerts on the object with mass 2m is equal to the force that the object with mass 2m exerts on the object with mass m. Therefore, the magnitudes of forces are equal despite the differing masses.