Suppose the Moon had twice the diameter but the same mass and same orbital distance from Earth. In that case, the high tides on Earth would be
A)higher.
B)lower.
C)unequal in size.
D)practically the same.
E)none of the above

Question

Quizplus · Accepted Answer

The height of tides is mainly determined by the gravitational force between the Earth and the Moon, which depends on their masses and the distance between them. The tidal force varies inversely with the cube of the distance between them, so doubling the diameter but keeping the distance the same would effectively reduce the strength of the tide by a factor of 8 (2^3). However, since the mass of the Moon has also doubled, the gravitational force between them would increase by a factor of 2, cancelling out the decrease in tidal force caused by the increased distance. Therefore, the high tides on Earth would remain practically the same.

Suppose the Moon Had Twice the Diameter but the Same