B Question about the solar system and gravitational forces

[Sundown444]

TL;DR Summary

Simple question about gravity and coordinates.

Alright, so I have a question. Now, on planets such as our Earth, there are a longitude and latitude as well as altitude. If I am not mistaken, I believe the latitude and altitude are part of what affects gravity, or weight, on a planet. Latitude makes it so that the object in question is lighter at the poles and heavier at the equator, and altitude makes it so that the gravity weakens the higher something goes and increases the closer it is to the center. Now...

What about the solar system? If the object were closer or farther from the sun, would they be heavier or lighter respectively? Likewise, if the object were above the plane where planets orbit or below it, being closer to either of the poles of the sun or at the equator of the sun while orbiting around it, would it be weaker or stronger depending on how close the object is to the equator?

Also, would this apply to the rest of the galaxy outside solar systems? Do I need to explain more or provide more statistics?

 

[mjc123]

What determines the gravitational field strength? Why is the weight different at the poles and the equator? Would this apply to an object in polar vs. equatorial orbit, at the same distance?

 

[Sundown444]

What determines the gravitational field strength? Why is the weight different at the poles and the equator? Would this apply to an object in polar vs. equatorial orbit, at the same distance?

I am not sure if I follow the last two questions. In the case of the first one in the solar system, though, I believe the strength of the sun's magnetic field would determine the strength of the gravitational field.

 

[mjc123]

Nothing to do with the magnetic field. What's Newton's formula for the gravitational force?

 

[Sundown444]

I am sure it is F=G (Gravitational Constant) x ((Mass 1 x Mass 2)/Radius Squared), where G = 6.674×10−11 m3⋅kg−1⋅s−2, unless I am missing something for planets.

 

[mjc123]

Yes. So for two bodies of fixed mass M1 and M2, what will cause the gravitational force to vary?

 

[Sundown444]

I say the radius would, if I am not mistaken. Say in this case, the radius of an object, which will be 70 kilograms, by the way, is 68.895 billion meters, roughly the distance from the sun to the planet, Mercury.

 

[mjc123]

OK. So how does this apply to
(i) an object on the surface of the Earth at the pole vs the equator?
(ii) an object in polar vs. equatorial orbit (at the same distance)?

 

[Sundown444]

What I was trying to say is, or ask: would being at a certain latitude that may not be at the plane where the planets orbit the sun affect the weight of the object like how being at the poles or equator at the Earth affects the weight of the object?

I still don't know what you mean by "at the same distance" for the second question, though. Sorry for not understanding.

 

[PeroK]

What I was trying to say is, or ask: would being at a certain latitude that may not be at the plane where the planets orbit the sun affect the weight of the object like how being at the poles or equator at the Earth affects the weight of the object?

I still don't know what you mean by "at the same distance" for the second question, though. Sorry for not understanding.

First, an object on the surface of the Earth is not in a gravitational orbit. The weight of that object is defined as the force between it and the Earth's surface. If the Earth were not spinning, then the weight would be constant across the globe. But, as the Earth is spinning some of the gravitational force is required to provide the centripetal acceleration. This is greatest at the equator and zero at the poles. This results in the object's weight varying across the Earth.

The planets are in gravitational orbits and technically have no weight - as they are not on the surface of the Sun.. There is only the gravitational force, which varies according to mass and distance; there are no other factors.

 

[Sundown444]

First, an object on the surface of the Earth is not in a gravitational orbit. The weight of that object is defined as the force between it and the Earth's surface. If the Earth were not spinning, then the weight would be constant across the globe. But, as the Earth is spinning some of the gravitational force is required to provide the centripetal acceleration. This is greatest at the equator and zero at the poles. This results in the object's weight varying across the Earth.

The planets are in gravitational orbits and have technically have no weight - as they are not on the surface of the Sun.. There is only the gravitational force, which varies according to mass and distance; there are no other factors.

Okay, I think I get it now. Just wanted to make sure. Thanks.