If the earth were a different shape, how would gravity be affected?

Question

If the earth were shaped like an ellipse, with the north and south polls being the points closest to the center and the equator most distant, where would one be more affected by gravity at the poles or at the equator? Normally I would say at the equator because you are further from the center of the earth, however, you are still on its surface, so there is plenty of mass between you and the center which also adds to the force fo gravity itself...

Answer 1

yes. Because centre of mass changes, the point where weight exist changes, which changes the magnitude of 'g'.

Answer 2

Wherever it is farther from the center, gravitational force is less and where it is nearer it is more.

That you can see in our earth too. At poles it is more and at equator it is less.

Answer 3

But...

The earth IS shaped like an ellipse!

That is why they have different numbers for the radius of the earth:

Equatorial radius (6378.1 km)

Polar radius (6356.8 km)

Volumetric radius (6371.0 km.)

You are equally "affected" the thing is...

At the equator, you have more force pulling you straight down and less force pulling you toward the polls.

At the poll you have less force pulling you straight down and more force pulling you toward the equators.

i.e.; This is a "SUM OF THE VECTORS" principle.

(Your weight is the vector to the center of the earth.)

The weight differences are not very big, but they are measurable.

Answer 4

I thought the earth is the shape it is because of gravity?  Thats why planets are round and not square, right?

Answer 5

Gravity seems to pull to the center of an object.  Most objects of any real size become round because this is the most stable shape for them.  However, asteroids and other large objects are often shaped very irregularly.

The further away from the center that you are, the weaker the pull of gravity becomes.  Therefore, on a massive object shaped like an ellipse, gravity would be strongest at the narrowest points.  However, the object would have to be truly enormous to see any noticeable difference.

Answer 6

your actually describing earth in reality. the pole are closer to the center, and the equator is slightly further away. gravity is higher at the poles because they are closer to the center.

Answer 7

i will tell as a physicist that the gravity will be on the equator most for example the us navy lives the earth to the moon or space as a physicist u will know that there is greater gravity on the air than on  space so  the further u go the lesser the gravity.

Answer 8

I think it would still be the same do to it's mass

Answer 9

No, the earths gravity would not be affected. But the farther away you are from the center of the earth, the less gravity there is. So if you where on and elliptical planet, the gravity would feel stronger at the poles and weaker at the equator.

Answer 10

it wouldnt

Answer 11

First off that question would become a true statement if it were backwards. Gravity affects the Earths shape. Once a body reaches a dwarf planets mass it become spherical. But for the sake of the question...

I am pretty sure you would be attracted to the center of mass. I drew out a few ellipses on a sheet of paper and it wouldn't make any sense for it be attracted to a foci or something. I am assuming you meant an ellipse rotated around the pole as an ellipse isn't a 3-D shape in itself. The poles would have the greatest gravitational pole and the equator would have the least due to the great angular momentum you would have because of the Ellipse Earth's rotation, not because you are farther from the center. This is because the poles would be closer to the center but there would be less matter underneath their feat, while someone at the equator would have more matter under their feet but it would be farther away.

And if you had a very distinct ellipse one would not be attracted directly to the surface relational to the person on the ground if you were not either on the poles or equator. It would be like living on the side of a mountain. If you fell you would just keep rolling and rolling.

Answer 12

As long as you are not inside whatever shape the earth is, the only factor that matters for gravity is the earth's mass and your distance to its center of mass.

Answer 13

gravity depends on BOTH mass and distance from the centre of the planet.

Answer 14

The earth is round(ish) due to it's own gravity. It loses out on being perfect sphere because the earth is held by the suns gravity, spinning it in  a circle.

This spinning creates centrifugal force which pulls the earth into a slightly eliptical shape.