All Questions
Tagged with newtonian-gravity planets
22
questions with no upvoted or accepted answers
2
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0
answers
64
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Most stable shape if Newtonian gravity was proportional to $r^\alpha$
Consider lots of mass in isolated 3D space, close to each other. Consider that only the gravitational force (Newtonian) exists. Also consider that there is no rotational motion.
It is evident that a ...
- 221
2
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2
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146
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A simple proof that under Newtonian gravity rotating massive bodies are ellipsoids?
Here is my attempt at deriving the shape of an idealized rotating massive body under Newtonian gravity, assuming that the gravity force points towards the center of mass and shape of the body is ...
- 513
2
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2
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240
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Tidal forces between Moon and Earth
I started studying about gravitation recently and I came across the fact that when finding the gravitational force between the earth and some point mass in space, we can consider the mass of the earth ...
- 167
2
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129
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How strong can tidal forces get?
I am imagining a planet the size of Earth being in close proximity to something of high mass such as a gas giant or a star, but ultimately I'd be more interested in how to figure this out myself.
So (...
- 121
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248
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Only gravitation and Newton's $2^{\mathrm{nd}}$ law needed to derive Kepler's laws?
It is known that Kepler's laws of planetary motion can be derived from Newton's laws of motion and his law of universal gravitation. However, are all of Newton's laws of motion necessary?
According ...
- 143
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 ...
1
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0
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74
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Find minimum radius of an asteroid before it becomes round using bulk modulus and hydrostatic equilibrium
How big must an asteroid be before gravity makes it round and hydrostatic equilibrium comes into the equation? Let's say that being a round planet requires a radius error of $\frac{\delta R}{R}$ that ...
- 11
1
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2
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123
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Is there a smooth transition from inverse quadratic gravity to linear gravity?
I can't remember exactly what it was, but I remember going through a problem in physics related to gravity on and inside a sphere, and found that inside, gravity acts linearly as a result of some ...
1
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22
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How severe would the consequences be if the earth's moon were wrenched from orbit?
The old TV series Space 1999 from the early 1970s seems to have resurfaced on Youtube reminding me of something I watched as a child.
It is one of those obviously ridiculous SciFi series (from the ...
- 2,572
1
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137
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Gravity train and fastest path
As a fun exercise to kill some time, I have been thinking in the gravity train. For a point mass falling through a tunnel dug from pole to pole in an spherically symmetric planet of radius $R$, the ...
- 915
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44
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Gravity formula inside a planetary core
I am trying to work through this problem so that I can understand how to convert from pressure values to radius values inside a planetary core in a code. The core has variable density depending on ...
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69
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Dynamic equilibrium of planets
We can describe statical equilibrium ( forces, moments ) in a cuboid $$ \Sigma F_x=0,\Sigma F_y=0,\Sigma F_z=0~$$ In dynamics can we describe similar dynamic equilibrium within an inertial ...
- 1,032
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1
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57
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Gravity train in other planets?
A Gravity train (https://en.wikipedia.org/wiki/Gravity_train) goes through a tunnel inside a planet that connects point A with point B. On Earth, the train would not gain enough impulse to reach the ...
- 2,462
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2
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47
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Lopsided planet
Something that has always puzzled me about Pangaea.
If we have a "roughly" spherical mass of solids, aren't two points on opposite sides approximately the same distance from the center of ...
- 369
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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 ...
