Final answer:
3. The Earth and the Moon exert a gravitational force on each other, leading to observable effects such as tides, and causing both to orbit around their common center of mass. The Moon's gravitational pull creates differential forces on Earth that distort its shape and affect the tidal movements.
Step-by-step explanation:
3. When we consider that the Earth pulls on the Moon and the Moon pulls on Earth, we're recognizing the presence of a gravitational force between them. This mutual attraction is due to gravity, which operates between any two masses, no matter their size.
The strength of this gravitational pull depends on the mass of the objects and the distance between them, following the inverse-square law, which states that the force decreases proportionally to the square of the distance between the objects.
Because Earth is not perfectly rigid and has a certain size, the Moon's gravitational pull is not uniform across its surface. This differential force causes Earth to distort into an oblate spheroid, with the long diameter pointed toward the Moon. This effect is most observable in the creation of tides, as water easily flows and creates a high tide on the side nearest to the Moon, and another high tide on the opposite side due to the Earth itself being pulled more towards the Moon than the water on the far side.
In compliance with Newton's third law, the mutual forces between Earth and the Moon imply that neither of them is stationary as the Moon orbits around Earth. Both bodies actually orbit around their common center of mass. The effects of the Moon's gravitational force on Earth are also evident in the slight 'wiggles' in Earth's path around the Sun, as well as in the periodicity of tides that correspond to the Moon's position and its orbit around Earth.