why does earth experience tidal twice per day rather than one?

Question

All I know is it has something to do with the gravity of moon. A explanation with mathematical model would be appreciated but not required. thank.

Answer 1

The moon pulls on the water and the earth. You can think of the moon pulling on the very center of the earth . When the water is between the earth and the moon, the strength of gravity is stronger on the water than the earth so there's a high tide. When the moon is on the opposite side of the earth from a point, the earth's center is closer to the moon. The moon pulls harder on the earth than the water, so the earth gets pulled more than the water and the water rises.