If earth is rotating on an axis...why haven't we fallen off by now..? are we rotating that fast?

Answer 1

the force of attraction is stronger than the outward force.

the world is very big, as is its spinnning velocity. its relative.

Answer 2

To put equations and numbers into the discussion above, and thereby get myself marked "bad answer" by dozens of people....

There are two effects at work, centrifugal "force" (which I put in scare quotes because it's an artifact of a rotating reference frame — you'll have fun with this if you take an AP physics course) and gravity.  Whichever one is stronger is the one which determines whether you'll stay put or fly off.

If you're standing on the earth and not falling off [*], some force is offsetting the centrifugal force of spin.  But how big is the centrifugal force?

Using a little differential calculus, the acceleration of an object moving around a circle of radius R at an angular speed ω is equal to ω²R.  Very simple, no (aside from the inconvenience of ω being in radians per second)?  So if you're standing on the equator (6380 km from Earth's center, more or less), going around at one circle (2π radians) per siderial day (86164.1 seconds; see link), your angular speed ω is 2π/86164.1.  Windows calculator says this is a fairly small number:

7.292115e-5 (I chopped off some decimal places).

Square this and multiply by 6,380,000 meters, and the acceleration comes out to:

0.03392 meters per second squared.

The acceleration of gravity pulling you down is about 9.81 meters per second squared.  So the answer is fairly simple:  the centrifugal force from Earth's rotation is about a third of a percent of the force of gravity even on the equator, where it's the greatest.

If you were moving around fast enough to fall of the Earth, you'd be in orbit.  That tells you about how fast you'd need to go:  faster than one revolution in 90 minutes.  It takes a little less speed up there at Space Shuttle altitudes, because gravity is slightly weaker due to increased distance (on the order of 10%).

[*] It's said that you're not too drunk if you can hold onto the floor and not fall off.  I think that can be generalized to the Earth.

Answer 3

The earth rotates at a speed of zero at the polar axis and approximately 1,000 miles an hour at the equator. Gravitational pull of the earth holds us on.

Answer 4

Earth's rotational period is 23 hours and 56 minutes. The axis is of course inclined. But because of the gravitatioal pull of the earth we stay on earth not falling. The rotation period is faster than our revolution time.

Answer 5

The earth rotates once every 24 hours and is about 24000 miles around.
24000 miles / 24 hours = 1000 miles an hour.
So, in a word, the answer to your question is YES.

Note: That is why the Sea Launch program launches from the equator, it gives the rocket a 1000 mph initial velocity.

Answer 6

Centrifugal force (the reason why water does not fall out of spinning bucket) and gravity (The force that pulls all objects to the fround)

Answer 7

Gravity is the answer. The gravitational force keeps us sticked to the ground.

Answer 8

the earths mass is so large, and since were born close to it, and our mass is small, we are attracted to the center of the earth, hence we dont fall off...even though its spinning, its a very small factor compared to gravity

Answer 9

its called gravity ask your teacher.. there's a little coiled up thing in your ear that keeps you from getting dizzy.. that's another thing to ask your teacher.

Answer 10

Cause we hang in there til we get tired then they put as in the Ground !