All Questions
Tagged with newtonian-gravity planets
311
questions
3
votes
2
answers
175
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On a Torus World and the force upon inhabitants
I am looking into torus worlds for fiction, and I know how to calculate the necessary speed to rotate, and necessary radius, for such a world to get a specific force of gravity.
But what I am ...
- 221
4
votes
1
answer
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Newtonian contribution to perihelion precession of Mercury
We have seen that the orbits of the planets around the sun can be
found, to a good approximation, by only considering a two-body system
(a planet and the sun) interacting through a central force. ...
- 717
1
vote
1
answer
71
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How do we find the centripetal forces of 3 planets revolving around a point given that they have the same mass?
Let's say we have three planets revolving around a point. We know that the force of gravity acting on all of these planets can be taken from $g = G{m_1m_2 \over r^2}$. We can derive the velocity of ...
0
votes
1
answer
121
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Body falling through Earth
Imagine a body with mass $m$ moves through a pipe through the centre of earth. The gravitational force is given by $\vec{F}=-C \vec{r}$ where $C$ is constant. I want to determine the 1D equation of ...
- 15
1
vote
2
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267
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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 ...
- 791
6
votes
1
answer
506
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Does gravity slow down sound (does sound travel faster downwards than upwards)?
I have read this question:
So assuming the heavier planet has the same atmosphere as Earth, and that we can treat the atmosphere as an ideal gas, the speed of sound on the heavier planet would be the ...
- 29k
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votes
0
answers
505
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Does the formula $v = \sqrt{GM/r}$ work for elliptical planetary orbits?
Suppose we have a central mass $M$ and a smaller mass $m$ orbiting around the central mass in an ellipse:
The other point is the other focus. We know that elliptical orbits have the central mass in ...
6
votes
3
answers
745
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Basic question about orbital speed
I was reading a Sci-Fi book recently and had a weird thought:
I know that objects closer to a gravitational well need to move faster to stay in orbit and objects further away move slower. But if you ...
- 81
0
votes
2
answers
753
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How to derive Kepler's third law of planetary motion using angular momentum of Earth around the Sun?
While I was trying to derive Kepler's third law of planetary motion, I tried the gravitational force for the Earth method which goes something like this:
$$\frac{mv^2}{r}=\frac{GMm}{r^2}$$
$$\...
- 115
0
votes
2
answers
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How does formula for universal gravitation between mass $M$ and mass $m$ collapse to $mg$ on Earth? [duplicate]
Can anyone give a mathematical demonstration of this? I assume it has to do with the fact that Earth’s mass is much bigger than the mass of any object on Earth, but I think it would be interesting to ...
- 556
0
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2
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214
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Simplest expression for gravitational flattening of Earth-like planet, from zero rotation rate to Earth rate, to within 10 percent error
Richard Fitzpatrick discusses the rotational flattening of a celestial body. A model that assumes homogenous density arrives at a difference between the Earth's equatorial and polar radii of 27.5 ...
- 21.4k
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0
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31
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What's the difference between Potential energy ($mgh$) and gravitational potential energy ($-\frac{GMm}{r}$)? [duplicate]
Yeah one is for measuring potential energy between the objects of two masses $M$ and $m$
We recently started studying about gravitation and I'm really confused when swtiching back and forth, or can we ...
27
votes
6
answers
16k
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Does gravity get stronger the higher up you are on a mountain?
So I saw this article stating that gravity is stronger on the top on the mountain due to there being more mass under you however I have read some questions other people have asked and most of the ...
9
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11
answers
5k
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Can a person on the equator jump up higher into the air at sunset than at sunrise?
I am wondering if a person on the equator can jump up slightly higher into the air at sunset in comparison to jumping up into the air at sunrise.
The reason for this would be that at sunset the Earth ...
- 478
-1
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2
answers
178
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Independence of Gravitational acceleration with depth if local density of earth is 2/3 of average density
Show That the acceleration of gravity in a vertical mine shaft is independent of the depth if the local density of the Earth is 2/3 of the average density. Assume that the Earth is a spherically ...
- 126