Final answer:
In a system with two masses at different distances from Earth's surface, subjected to a non-uniform gravitational field, the center of mass and the center of gravity would not coincide due to the varying strength of Earth's gravitational field with distance.
Step-by-step explanation:
The question concerns the concepts of center of mass and center of gravity. These two points coincide for objects in a uniform gravitational field. However, in a non-uniform gravitational field, they will not generally coincide. Considering a system with two masses located at different distances from Earth's surface will result in a non-uniform gravitational field because the strength of Earth's gravitational field varies with distance. Therefore, the center of mass and the center of gravity would not coincide. The correct answer to the student's question is B. No, they would not coincide.
The center of mass is a point that corresponds to the average location of the mass of a system. On the other hand, the center of gravity is the point where the gravitational force can be considered to act. In the case of two masses at different distances from the Earth, the non-uniformity of Earth's gravitational field will cause differential gravitational forces on each mass, which shifts the center of gravity towards the mass closer to Earth.