All Questions
88
questions
0
votes
1
answer
21
views
Can we treat the entire mass of the spheroid as being concentrated at its center?
I know that to find the gravitational force between two objects, if either of them is a sphere, we can assume its mass to be concentrated at its center and use the formula for gravitational forces for ...
- 207k
8
votes
5
answers
290
views
What is the gravity in the center of Earth?
Let's suppose the earth is a perfect sphere and let's ignore its rotation and movement.
What would happen if I would be in the center of the earth? Would the gravity be zero in any direction so I ...
- 25.3k
2
votes
3
answers
149
views
Would a gyroscope have solved the longitude problem?
So I was thinking about the longitude problem, which was the problem of determining the longitude at sea. It caused great problems in sea navigation. See: https://en.wikipedia.org/wiki/Longitude#...
- 49
0
votes
1
answer
120
views
Can gravity of planets besides Sun and Moon affect tides on Earth?
The tides in some places on Earth are over 50 feet. If the gravity from Venus had a ten thousandth the affect of the Sun and Moon on a 50 foot tide it would make a difference of one twentieth of an ...
- 32.9k
16
votes
6
answers
4k
views
If another planet was opposite Earth, would we be able to observe it?
Imagine another Earth-sized planet, in the exact same orbit as Earth, but 180 degrees out-of-phase. In this arrangement, at all times, you would be able to draw a single straight line through space ...
- 204
3
votes
1
answer
53
views
Does a planet's "equatorial bulge" induce any kind of motions or currents in the atmosphere?
Rotating planets, like the Earth, are not perfect spheres but are instead oblates. This affects both the crust and the atmosphere, creating a bulge in the equator 1.
I was wondering if there are ...
- 21.4k
2
votes
2
answers
356
views
Is $F=mg$ derived from Newton's law of universal gravitation $F=Gm_1m_2/r^2$?
If so, that means gravity is only 9.8 m/s^2 at the surface of the earth?
- 11
1
vote
2
answers
267
views
How close can Jupiter be to Earth without making Earth unhabitable? [closed]
How close can Jupiter be to Earth without making Earth unhabitable? What's the closest distance possible? Can Jupiter be twice or three or four times as close to Earth as Mars without having any ...
- 21.4k
1
vote
0
answers
15
views
If the rock boundary exists, how did the planet Theia manage to collide with Earth? [closed]
Because it wasn't orbiting it, but in an errant orbit, but coinciding with that of the earth.
Much of its matter was absorbed by the Earth, and part was thrown into space, grouping together and ...
- 29
0
votes
1
answer
62
views
Will the Earth ever stop rotating?
Will the Earth ever stop rotating or will it rotate for the entire lifetime of the universe (assuming that the Sun didn't exist, so the Earth would survive to the Red Giant phase)?
- 2,000
2
votes
1
answer
96
views
Are there any types of winds or waves that are produced just by Earth's rotation?
Are there any types of wind or waves caused/produced only and exclusively by Earth's rotation? Not influenced by Earth rotation, but produced solely by it?
In the case of waves, are Rossby waves 1 and ...
- 2,462
1
vote
1
answer
88
views
What would happen if the Earth rotated at the rate required to achieve orbit at its radius? I.e ~7k m/s instead of ~460 m/s
To achieve a circular orbit, you need to have a velocity of $$v = \sqrt{Gm/r}$$ which is about 7 km/s at the Earth’s radius, but the Earth’s rotational speed is only about 460 m/s (by taking the ...
- 4,170
0
votes
1
answer
379
views
Drift of Earth's orbit?
How much has Earth drifted (inwards or outwards) from its orbit about the sun? Or has Earth has not moved at all, compared to, say, 1000 years ago? 10,000 years ago?
- 2,646
1
vote
1
answer
81
views
What's responsible for the earth to rotate and for the objects on it to rotate with it? [duplicate]
Three questions arose to me:
The first is what is responsible for the earth spinning? Is this just newton's first law in action - having been formed out of the material in the cluster of clouds after ...
- 207k
0
votes
0
answers
136
views
Distance between two points on Earth (arc length) doesn't increase with altitude (radius) according to GPS
Consider the following example:
Point A has coordinates 45 lat, 0 long. Point B has coordinates 45 lat, 2 long. Both points are 5000 ft above sea level. The distance between them is X.
Point C has ...
