Why are there two high tides a day about 12 hours apart from each other?
earth revolves around the sun once during that time.
earth rotates entirely on its axis once during that time.
the moon revolves around earth once during that time.
the moon’s orbit is in line with earth’s orbit twice a day.

Earth rotates entirely on its axis once during that time.

Explanation:

The earth completes a rotation on its own axis every 24hours. This is particularly very important in understanding the change in tides during the day.

As we know, the moon revolves round the earth. Due to the mass of the moon and the earth, there is a gravitational pull between those two masses. This force becomes very great when the earth and the moon are closer. The pull is lower as they move apart in their orbit.

Once in 12hours in a day, the moon is very close to the earth and it exerts its maximum pull on earth. This is the period of high tide.

At another time, the moon is far away in orbit from the earth and its pull is minimum. This the period of low tide.

Earth rotates entirely on its axis once during that time.

Explanation:

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