Thread: centrifugal force at equator?

ok, since the world is spinning as fast as it is, shouldnt centrifugal force pull stuff towards the equator?

and wouldnt stuff at the equator weigh less since some of the gravity acting on the body is cancelled out by the centrifugal force?

if earth radius increased to a height of geosinchronous orbit and kept its mass i think people in the equator would feel 0 g

when i asked my teacher this very same question he answered newton stated gravity was function of distance to earth cog

in the pole distance is shorter than in the equator, i disagree with this though

Originally Posted by luxtpm

if earth radius increased to a height of geosinchronous orbit and kept its mass i think people in the equator would feel 0 g

when i asked my teacher this very same question he answered newton stated gravity was function of distance to earth cog

in the pole distance is shorter than in the equator, i disagree with this though

Technically, your teacher is correct. Gravity does depend on the distance to the Earth's CoG. Since the Earth is an oblate spheroid, gravity is stronger at the poles. This is secondary to the lessening of weight at the equator due to the Earth's spin. (which technically is not a lessening of gravity)

As far as this difference goes, it works out to about 0.034 m/s² (0.34% of a g)

As far as things being pulled towards the equator, the surface of the Earth is at equipotential, meaning that there is no tendancy for things to move toward the equator.

Originally Posted by Janus

As far as this difference goes, it works out to about 0.034 m/s² (0.34% of a g)

I'm surprised it's that big. That's actually pretty significant. Maybe not something you could notice, but you could definitely measure a notable difference in how long it takes your pendulum to swing back and forth or something.

Originally Posted by zach

ok, since the world is spinning as fast as it is, shouldnt centrifugal force pull stuff towards the equator?

and wouldnt stuff at the equator weigh less since some of the gravity acting on the body is cancelled out by the centrifugal force?

You are correct that the effect of 'centrifugal force' is greatest at the equator. I have not worked out the difference in weight, however the effect in terms of speed is important for the lauch of rockets going to orbit. That is why launch facilities tend to be located as near the equator as is practical given other concerns. It is why the U.S. launches most satellites from Cape Canaveral in Florida (polar orbiting satellites are launched from Vandenburg AFB in California) and why the French established the Ariane launch fracility at Kouru in French Guiana.

You might have learned that . That is only an average. On the equator it is about 9.79, and on the poles about 9.83. It also changes with altitude and even the composition of the rock beneath you has a small influence. You can read all about it here.

It's not so much the composition but volume and density of the rock beneath you. Also it depends on whether or not the moon is above you, behind you, or to one of the sides. The sun has an effect as well, along with everything else in the universe, just to a very small scale.

in case of earth, centripetal force i=centrifugal force. it is not a free flying object like a stone. it has axis also.