All Questions
Tagged with newtonian-gravity celestial-mechanics
372
questions
2
votes
1
answer
72
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Gravitational collapse - proof that energy dissipation is required?
As an undergraduate, I took a short course on astrophysics, where I encountered the Jeans mass. This is the critical mass for a spherical cloud of interstellar gas above which the cloud is predicted ...
- 317
0
votes
0
answers
30
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Restricted 3-body: one large mass and two smaller ones
A restricted 3-body problem is usually understood as two large bodies and one much smaller one that doesn't affect the motion of the other two.
I am curious about a 3-body problem with one large body, ...
6
votes
7
answers
1k
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What changes the velocity perpendicular to radius in an elliptical orbit?
I'm working currently on a problem that asks to justify that angular momentum and kinetic energy conserves for a planet in an elliptical orbit. Although I've been taught that angular momentum should ...
- 69
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1
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61
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Find eccentricity of orbit given the velocity and the semi-major axis
Is it possible to calculate eccentricity of orbit knowing only the semi-major axis and the velocity of both celestial bodies? If not, what other additional information is required.
Does the fact that ...
- 38
2
votes
0
answers
37
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When are two object guaranteed to keep getting further and further away?
In a two-body problem, it is known (if I understand correctly) that if the specific orbital energy of the system is $\varepsilon \geq0$, then the objects must eventually escape each other. My question ...
- 125
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votes
1
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43
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Speed of satellite in elliptical orbit [closed]
A satellite $S$ orbits a planet of mass $M$ in an elliptical orbit. At perihelion, $S$ has a tangential velocity of $v_1$ and is distance $r_1$ from the planet. At aphelion, $S$ has a velocity of $v_2$...
- 3
1
vote
1
answer
64
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Tidal forces in the early solar system
I'm reading a book called "Gravity from the ground up" by Bernard Schutz. I don't understand this section from Investigation 13.3 on page 159, which discusses the formation of the solar ...
- 11
0
votes
2
answers
61
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Average Speed in one half of an elliptical orbit
I was wondering whether the average speed along one half of an elliptical orbit (say in a star planet system) had a closed form exact solution using Kepler's laws.
My approach was using the ...
2
votes
2
answers
124
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Orbiting body around a star
Let us assume there's a body with mass $m$ and velocity $v$, at a distance $r$ from another body of mass $M$. The velocity vector is perpendicular to the radial vector. With these values, how do we ...
- 91
1
vote
1
answer
78
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Two bodies orbiting around barycenter
There are two bodies with masses $m_1$ and $m_2$ orbiting around barycenter. Distances to both bodies from barycenter are $r_1$ and $r_2$ . First body has known velocity $v_1$ as on the picture :
My ...
- 11
0
votes
0
answers
24
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How does moving the pericenter affect the apocenter?
A perfectly circular orbit of a constant height (distance from the center of mass of the orbited planet) around a perfectly spherical planet with smooth surface and no gravitational anomalies will ...
4
votes
1
answer
727
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Do orbits with positive energy tend to infinity?
Consider any potential field $$V = V(x)$$ (not limited to gravitational potential field, but we only consider time-independent ones) in 3-d space that satisfies the following conditions:
The ...
- 43
0
votes
0
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30
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Different transfer trajectories between same planets
I was working on desmos drawing transfer trajectories between the earth and moon. I managed to draw both the trajectories but i noticed something rather odd. The transfer orbits were different ...
- 91
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votes
1
answer
48
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Dynamics of Eliptical Orbit
For a circular orbit, we can resolve the forces acting on it along the radial and tangential axes. However, along which orthogonal axes should I resolve the forces acting on a body traveling in an ...
0
votes
2
answers
83
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Newtonian mechanics doubt
While solving a particular classical mechanics problem , I was told that for a system of particles to be bound under their mutual forces, their initial energy (With Respect To the COM) must be less ...
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