Why does the sea have tides?

Answer 1

Because the wind blows the water and it makes he waves.

Now the explanation as to why this happens.

Both the air and water have a viscosity associated with them. This means they stick to things that they move against. At the interface between the moving air and the essentially unmoving the water, that moving air molecules tug at the water's surface a tiny bit (even of the water is perfectly flat). This is a boundary layer effect and is similar to the drag that is a problem with fast cars and jet aircraft. The drag moves the water a bit, but as it does the water forms bumps (like a sheet when you move your hand over it). The humped up bits catch more wind and become bigger eventually becoming waves.

Strangely enough (just like the sheet) the water does not move forward during this event, just the shape of the wave.

Answer 2

water waves can be wind generated. they are also caused by the movement of the earths crust.

and poop also changes it too.

Answer 3

It's because of the moon. That's all I really know why there are waves

Answer 4

The sea has tides because the moon's gravity draws the oceans into an oval around the Earth, creating a bulge of water on each side of the world.

Answer 5

Because wind makes the water to move. Harder the wind, bigger the waves. Also the sea floor shape affects the wave size.

Answer 6

There are waves in the ocean because the Moon's gravity pulls the earth and causes the earth's tilt to move differnt way. This causes the waves to have high tides and low tides.

Answer 7

Waves and tides are caused by the gravitational pull of the Moon.

Answer 8

The wave on the ocean is caused by the wind.