# Why does the sea tide and ebb, and where does the seawater go after ebb?

2020-01-10 | Zhong Ming talks about science original |

Newton's mechanics has two important laws, of which Newton's first law is that when all objects are not subjected to a force, or the total force is 0, the object always remains stationary, or moves in a straight line at a uniform speed.

When an object is subjected to a force, it will change its state of movement. For example, the reason why a bicycle can travel is because a person exerts a force; the reason why a bicycle stops because of the friction.

The same is true for the sea. If the water in the ocean receives 0 force, the water in the ocean will be very calm; however, in life, the water in the ocean often ebbs and flows. It is clear that there is a force in nature.Has changed the state of motion of seawater, so what exactly is this force? Why can it exert influence on seawater all year round?

Why does the sea ebb and flow?

Actually, the reason why seawater will tide is related to the gravity of the moon, and it is also called tidal force.

We know that force has a direction, and the gravity and gravity on the earth both point to the inside of the earth, so for us, "below" refers to the inside of the earth.

But for the moon, the gravitational direction of the moon is the interior of the moon. If it looks from the earth, the "below" of the moon is the sky.

that is, any object on the earth will be subject to two forces, that is, the gravity of the earth and the moon the sun and other gravitational forces are too small to ignore here. And the direction of gravity of the earth and the moon is againThe opposite is true. Which force should the objects on the earth be affected the most deeply?

If the object is more affected by the gravity of the earth, then the object on the earth will stay on the surface of the earth. If the object is more affected by the gravity of the moon, then it will fly to the sky under the gravity of the moonIn fact, this is the same problem that Newton thought about at the beginning: Why would a ripe apple not fall to the sky, but fall back to the ground? After Newton's meditation, he finally came up with a formula of gravitation through a series of studies :

He believes that the magnitude of the gravitational force to which an object is subjected, the mass of the two objects, and the square of the distance between the two objects, the greater the mass, the greater the universal gravitation between them, and the longer the distance, the smaller the gravity.

In other words, the objects on the earth will be affected by both the gravity of the earth and the gravity of the moon, but because the mass of the moon is small and the moon is too far away from the earth, the objects on the earth are mainly affected by the gravity of the earth.Be honest on the ground.

But water is different. We know that water is liquid and has no specific shape. When the moon ’s gravity is slightly more, the surrounding water will surge together to form a high tide. At this time, the amount of water in other places is less.Low tide will form. The sun also has a tidal force on the earth, but the tidal force provided by the sun is too small, and the changes in the earth ’s ocean tides are mainly provided by the moon

On the other side without the moon, due to the rotation of the earth, an orgasm will also form, that is, the earth will form an orgasm in two places at the same time.

Where did the seawater go after the ebb?

If we look from a fixed place, after the tide recedes, they return to the ocean, but the coastline of the ocean has not risen, so where did the seawater after the ebb tide go?

Actually, the seawater after the tide has formed a high tide elsewhere.

We know that the moon is orbiting the earth at all times. When the moon rotates, the seawater in the ocean will converge. Because of this, the water on the earth has not spread to the land, forming a disaster..

Actually, do you know? The ebb and flow of the sea also slows down the rotation speed of the earth. We know that in the process of seawater formation of tidal water, there will be friction between water molecules. In addition, seawater beats the coast.It will dissipate the energy of the earth and dissipate it into the universe in the form of heat. In this way, the kinetic energy of the earth is gradually consumed and the speed of rotation is gradually slowed.

At the place where the area just formed, the speed of the earth's rotation was 8 hours. During the dinosaur period, the speed of the earth's rotation was 20 hours, and today's rotation is 24 hours.

If the earth ’s history is long enough, the moon will lock the earth ’s tides, that is, one day equals one month.

At present, the earth has locked the moon tide. The reason for the tide lock is the same as that for the moon tide. The reason why the earth locks the moon tide first is because the mass of the earth is large and the tidal force on the moon is also large.

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