The path a body takes while moving through space under the influence of the gravitational forces of other bodies

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1answer
21 views

Angular momentum for elliptic path in 2D isotropic oscillator

Assume a 2D isotropic oscillator, i.e $$U = \frac{1}{2}m\omega^2(x^2+y^2),$$ and assume for simplicity that the oscillator performs elliptical motion, with major axis $A$ and semi-major axis $B$. My ...
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1answer
42 views

Will the Earth ever show synchronous rotation? Why and when?

In this answer to the question "why does the moon have the same rotation and revolution periods?", we read: The mass and speed of rotation of the Earth influence the moon in that some of its ...
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2answers
64 views

Planets potential [duplicate]

I'm a physic student of Italy. I'm moving my first steps in this beautiful world, and as every new entry, my simple and stupid questions are sometimes not so simply resolved. I'm trying to know the ...
1
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0answers
34 views

Semi-major axis , specific mechanical energy, its period and velocity at Apogee and Perigee and what the difference is [closed]

Hi im needing some help with two questions could you please show the formula and the way its solved?Thanks PS:Could you also explain what the difference of velocity and apogee and perigee? 1.)A ...
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0answers
54 views

Lyapunov stability of circular orbits

I'm studying Classical mechanics on Arnold's "Mathematical Methods of Classical Mechanics". In a problem i'm asked to find for which $\alpha$ the circular orbits in the central field problem are ...
2
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2answers
115 views

In what direction should you throw a 1Kg uniform sphere in order to put it into lower earth orbit? [closed]

If you are standing on earth's surface, in what direction (and at what speed) should you throw a 1Kg uniform sphere of radius 0.1 meters in order to put it into lower earth orbit? Assume that there ...
2
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1answer
42 views

Why is the matter orbiting a black hole in the shape of a disk? [duplicate]

More generally, if a blackhole is a singularity...a point in space...why is matter only circling in a flat disk-like region. It would seem to me matter would circle it in a sphere surrounding the ...
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2answers
81 views

Tension of a string rotating a ball in a circular motion?

A ball of mass 5kg is attached to a string of length 120 cm and rotating vertically at a speed of 10 cm/s. what is the tension of the string when the ball is farthest to the right from the ...
2
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1answer
27 views

Can a tidally locked planet have a horizontal rotational axis?

Is it hypothetically possible for a planet to be both tidally locked, and still have a rotation "horizontally"? Where the substellar point would in effect be like the point of a top, spinning and yet ...
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2answers
52 views

Kepler Orbits: Equal areas in equal times [closed]

I've written some python code to simulate a Kepler orbit. Every 50 time-steps I draw a radial vector from the centre of the sun to the centre of the earth, as shown below. However, my ...
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2answers
51 views

Where is the space elevator falling? And the cable holding it?

I guess the concept of a space elevator is pretty well known. The idea, first published by Konstantin Tsiolkovsky in 1895, and popularized (among others) by Arthur C. Clarke in The Fountains of ...
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2answers
54 views

Does orbital motion cause rotation?

Assume the moon was flying freely in space, and not rotating at all. If if then happened to pass earth at just the right distance and velocity to fall into orbit, would its absolute rotation be ...
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0answers
50 views

Does Earth eclipse the Sun at the L2 Lagrange point?

Is Earth's diameter large enough to eclipse the sun at the L2 Lagrange point? Or does the sun shine around the edges of the earth? I understand the useful area of the L2 Lagrange point is somewhat ...
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1answer
67 views

Gravity and elliptical orbits

All orbits are elliptical and special orbits are circular (like when both bodies have the same mass or when the second body's mass is negligibly small). In a circular orbit centrifugal force (which I ...
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1answer
81 views

Speed of satellite when it falls freely on the surface of the earth [closed]

I am a high school student in my final two years before university. I have a question which I do not know how to approach. Any help would be appreciated. Thanks! "If an artificial satellite is ...
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0answers
24 views

Orbital period of a satellite in Kerbal Space Program

Let me start off by saying I am really bad at maths and physics, but lately I have been trying to calculate the orbital period of a satellite I have put in orbit around a planet called Kerbin in a ...
1
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1answer
48 views

Calculating orbits with varying laws of physics? [closed]

The general way planets orbit stars in our universe is determined by the inverse square law and the three laws of motion. Both the inverse square law and the three laws of motion are the reason that ...
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1answer
23 views

Seasons of Earths Orbit

I live in Northern hemisphere. Closer to the sun during winter. Planet traveling fastest in orbit. Does this mean a shorter winter season compared to the south?
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1answer
78 views

Bohr radius question [closed]

I'm doing a homework problem where it asks to calculate the diameter of a hydrogen atom with $n=600$. I used the equation $r=\frac{n^2a_0}{Z}$ where $a_0=0.529e^{-10}m$. Solving for $r$ yields: ...
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2answers
51 views

Why is there ice at the Earth's poles? [duplicate]

I beg your pardon for such a silly question, but I've never really understood the explanation they gave in the Geography textbooks. If the slanting Sun's rays due to the Earth's axial tilt can cause ...
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0answers
50 views

Finding the distance a spaceship would travel given a time of departure and velocity

Let's say a spaceship leaves Earth at a day t and with velocity v. Is there a way to know how many kilometers it will cover to arrive on Mars? This would be a trivial question were it not by the fact ...
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0answers
37 views

Could a satelite be pulled away by gravity while the object it was orbiting keeps unaffected in its own orbit?

I'm asking this, since I try to educate my self a bit in the field of astrophysics. From my point of knowledge the by title given scenario could occur. But I haven't yet read anything that sounded ...
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2answers
87 views

How has the world remained in balance?

In the center of our galaxy, there is a Supermassive black hole. We were told in early astronomy units of school that black holes are giant vacuums that will absorb/consume the area around it. My ...
2
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1answer
45 views

Gravity well and constant total energy in circular orbit [closed]

According to this question, the total energy of an object in a circular orbit in a $1/r^2$ potential does not depend on the radius of the orbit. However, if you look at "circular orbits" in a gravity ...
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1answer
70 views

Small particle rotating around neutron star

First let me say I have read the article at "users.ictp.it › lns003 › Ruoff › Ruoff.ps.gz" about a small particles orbiting a neutron star and causing excitation of different modes of gravitational ...
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1answer
21 views

Latitude from initial conditions

I'm a programmer trying to model satellite orbits. What formula can I use to determine the latitude of a satellite after a quarter orbit, given the initial launch latitude and inclination? For ...
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1answer
107 views

How much force would it take for you stop the Moon from crashing into the earth once it has started to fall?

In my previous question, I asked how much force it would take to destabilize the Moon's orbit enough for the moon to start falling into the Earth and collide. Assume this has already happened. Now, ...
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2answers
86 views

Why is meteor speed what it appears to be?

Is the speed of a meteor through our sky because of the speed of the earth's axis rotation, or because the meteor is speeding towards us at that speed?
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4answers
7k views

Can the Earth leave orbit if the population of humans and other live forms increases?

I don't know a lot about physics, but this seemed like the correct place to ask my question. I apologize in advance if it is a ridiculous one. It's actually a two part question: If the population ...
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1answer
74 views

How much force would be required to destabilize The Moons orbit enough for it to crash into the Earth?

It is known that the moon slowly drifts away from the Earth. How much force would be required to destabilize it in the opposite direction enough for it to accelerate and crash into the Earth? What ...
1
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1answer
65 views

Generation of artificial gravity by rotation

I have been trying hard to understand how Artificial Gravity is produced by Rotating a satellite around its own axis. Thus far, I have understood (probably wrong) that as a satellite is spun, walls ...
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0answers
24 views

Topic on relativistic celestial mechanics [closed]

I have to do a small 10-15 minutes presentation about celestial mechanics, and I am searching for a topic. As a mathematician my background in physics is not very extensive, but I have some notions ...
0
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1answer
23 views

What orbital elements would show earth orbiting in the opposite direction?

Would earth rotate in the opposite direction if inclination and argument of periapsis were 180 degrees? Looking at this diagram: https://en.wikipedia.org/wiki/Argument_of_periapsis Thanks!
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26 views

Initial guess for calculating the Universal Variable Formulation of the two-body Kepler problem

I am trying to simulate orbits using the Universal Variable Formulation of Keplers two-body problem, using the algorithm provided by Howard curtis in Orbital Mecanichs for Engineering Students as per ...
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0answers
51 views

Solution to gravitational two-body problem in case of hyperbolic orbits [closed]

Given two bodies and their positions and velocities at a given time $t_0$, as well as their masses, and the knowledge that their relative velocity is high enough that they will not be gravitationally ...
1
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1answer
132 views

Prove that time for planet to fall into the Sun equals $\left( \frac { 1 }{ 4\sqrt { 2 } } \right)$ of the planet's period [closed]

If a planet was suddenly stopped in its orbit supposed to be circular, show that it would fall onto the sun in a time $\left( \frac { 1 }{ 4\sqrt { 2 } } \right) $ times its time period. I am ...
3
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1answer
65 views

Second Kepler's law implies that constant velocity

I was trying deduce that if we suppose that the planet's orbits are circular and de Kepler's secong law is true: A line joining a planet and the Sun sweeps out equal areas during equal intervals of ...
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1answer
46 views

How a wheel move on the earth?

I was wondering how a wheel move on the earth ,I mean if friction causes it moves so what causes it stops after a while without any pushing force? I think that the direction of the friction force is ...
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0answers
42 views

Orbit of a planet

Can a planet move around a star in an exact circle? Does Kepler's laws prevent this from happening. Answers with mathematical base will be accepted.
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3answers
82 views

Gravity effects when deleting stars or planets

In one of the latest SCIFI movies, they collect a star absorving it entirely in a kind of planet size gun/machine. As mass cannot disappear, I assume it was just concentrated inside their machine ...
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1answer
108 views

Relation between eccentric and true anomalies

If $v$ is the true anomaly and $E$ the eccentric anomaly, how can I show that $$\frac{dv}{dE}=\frac{b}{r}=\frac{\sin v}{\sin E}~?$$
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1answer
67 views

What powers a comet? [closed]

I know that a comet is a ball of ice, and I have tried the NASA page. http://spaceplace.nasa.gov/dr-marc-solar-system/en/#/review/dr-marc-solar-system/comet-power.html but they swerve around the ...
0
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1answer
64 views

Why do the stars in a binary system, revolve diametrically opposite to each other?

I encountered this question, as I was reading up on Gravity. The author of my textbook says that the stars orbit a common centre which is their center of mass. I somehow think that this fact might ...
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2answers
44 views

Can outgassing produce a significant thrust on a space ship?

There are a variety of materials that outgas in the atmosphere, and I imagine they would do so even more in the vacuum of space. I imagine an object in space would experience a small force as ...
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0answers
24 views

Laplace's method to determine orbits

I am trying to do the second problem by Laplace's method, it is in spanish but the only thing that matters are the asteroid's observations and the coordinates of Earth ...
3
votes
1answer
45 views

How are orbits made stable

I understand the concept of object staying in some orbit due to centrifugal force and gravity. However I do not understand how is orbit of a body like satellite or planet has perfect balance between ...
1
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1answer
55 views

Can a planet's orbit around a star be simulated? [closed]

Say I know all parameters like density, size, rotational velocity of a planet, could I predict its orbit around a star where I also know parameters of it? I want to design a simple model of the solar ...
1
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3answers
102 views

How to predict the location of a planet at a given time? [closed]

I am trying to create a simple two-dimensional computer simulation of a planetary system. While I've been able to understand Kepler's Laws of Planetary Motion, I do not know enough about the formulas ...
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2answers
57 views

How does the decaying orbit of a satellite maintain its orbit as it descends, as opposed to crashing straight back to Earth?

I understand that as a satellite in low-Earth orbit experiences atmospheric drag, it is slowed down. Therefore it no longer has the velocity to maintain its orbit at that point, as per the orbital ...
0
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3answers
71 views

How is Earth orbit possible? [duplicate]

What force other than gravity acts on objects in Earth orbit? Without such force, continued orbit would be impossible, as the object would be drawn to the Earth.