why does earth rotate?

Answer 1

The Earth is rotating around an axis (called its rotational axis). Some objects rotate about a horizontal axis, like a rolling log. Some objects, such as a skater, rotate about a vertical axis. The Earth's axis is tipped over about 23.5° from vertical.

How do we define up and down in space? What would "vertical" mean? For the Earth, we can think of vertical as straight up and down with respect to the plane in which the Earth orbits the Sun (called the ecliptic).

Earth's rotational axis points in the same direction relative to the stars, so that the North Pole points towards the star Polaris. Think of the Earth as a spinning top, tipped over to one side. Over very long time periods (thousands of years) the direction of Earth's axis slowly changes due to precession.

The Earth rotates around once in 24 hours - that's a rate of 1000 miles per hour!. The time it takes for the Earth to rotate completely around once is what we call a day. It's Earth's rotation that gives us night and day.

Answer 2

The core is what causes the rotation of the earth.

Answer 3

Our everyday experience teaches us that an object must be "pushed" by a force in order to keep it moving. Otherwise, it will slow down and eventually stop. But this intuition is absolutely wrong. If an object is moving, then a force is required *to slow it down or stop it*, not to keep it moving. (Hence, "Objects in motion tend to stay in motion. Objects at rest tend to stay at rest.") In our everyday experience, it's the force of friction that tends to stop Earth-bound objects from moving forever. But for the Earth rotating on its axis, there is no force working to counteract the rotation (except the tidal effect of the Moon, but that's working very slowly), so you don't need to have any input energy to keep it spinning.

Answer 4

It is coasting forever in the frictionless vacuum of space on the momentum it got when it was formed billions of years ago. There is no power source. None is needed since there is no friction to slow it down. (Actually, there is a small amount of friction due the the Moon and the tides, and that slows Earth's rotation by a very, VERY small fraction of a second each year.)

Answer 5

Here's a good explanation:

http://www.phy6.org/stargaze/StarFAQ1.htm#q26

(Search for the question "Why does the earth rotate?")

Answer 6

because the center of the earth is a spinning whirling mass of molten rock and iron so it kinda pushes the earth

Answer 7

U see jus revolving around the sun is so boring! That is the reson earth roates...jus to make it a lill interesting :)

Answer 8

coz if earth does not rotate we will not have day and night, ,the sun,stars ,moon will not rise in east and set in west.....

Answer 9

every night,my parents room rumbles,always when the sun is sleeping,i think the rumbling turns the earth and makes the sun wakes up again.

Answer 10

So it can move and let the sunshine see every place on earth.