Orbits Definition and 487 Threads

Homework Statement 1 a) Prove that the group (nZ, +) acts on Z by a*g = a + g for all g in nZ and for all a in Z. b)What are the orbits? c)How many orbits are there? Do the set of orbits remind you of anything in number theory? Homework Equations not sure The Attempt at a Solution...

Homework Statement Show that the angular momentum in circular orbit around a mass M can be written as functions of just the masses, the orbit radius, and G. Homework Equations L = r x p = r x mv L = Iw The Attempt at a Solution I had no trouble showing that the total...

Homework Statement 1. Which of the following statements about a circular orbit are true? (The planet is orbiting around the star.) a. At any instant the momentum of the planet is tangent to the planet's trajectory. b. The magnitude of the planet's momentum is constant. c. At every...

1. Which of the following statements about a circular orbit are true? (The planet is orbiting around the star.)a. At any instant the momentum of the planet is tangent to the planet's trajectory. b. The magnitude of the planet's momentum is constant. c. At every instant, dvector p/dt points...

Can someone tell me what the formulas are for the x,y & z co-ordinates of a planet on its elliptical orbit of the sun? I don't mind astronomy terms (I'm no expert on them but have a basic knowledge and will look up and learn any I don't know). It's not homework, just something that's doing...

Are De-Broglie stationary orbits different from Bohr's stationar orbits? I really haven't been able to figure out.

Homework Statement Show the the total energy of a parabolic is zero. Show that the energy of a hyperbolic orbit is positive.Homework Equations r=\frac{L^2}{GM\mu^2*(1+e cos\theta)} v^2=GM \left (\frac{2}{r}-\frac{1}{a} \right )The Attempt at a Solution E=T+U=\frac{1}{2}\mu v^2 -\frac{GM\mu}{r}...

Planet Orbits, finding radius HELPP! Homework Statement The planet Mars has a mass of 6.418*1023kg and completes an orbit around the sun in 687 days. The sun has a mass of 1.99 * 1030kg. what is the average radius of the orbit of mars? Homework Equations Force Gravity = G*(m1m2)/r2...

Homework Statement Communications satellites are placed in a circular orbit where they stay directly over a fixed point on the equator as the Earth rotates. The radius of the Earth is 6.37 x 106m, and the altitude of a geosynchronous orbit is 3.58 x 107m. What are (a) the speed and (b) the...

Homework Statement Let H be a finite subgroup of a group G. Verify that the formula (h,h')(x)=hxh'-1 defines an action of H x H on G. Prove that H is a normal subgroup of G if and only if every orbit of this action contains precisely |H| points. The Attempt at a Solution I solved the first...

Homework Statement If G is a finite group which acts transitively on X, and if H is a normal subgroup of G, show that the orbits of the induced action of H on X all have the same size. The Attempt at a Solution By the Orbit-Stabilizer theorem the size of the orbit induced by H on X is a...

Hi, I'm actually a Design Engineer but I find the topic of Relativity extremely interesting and I was wondering if somebody could give me some guidance on this. If Planets and Stars (due to their mass) 'warp' Space-Time then this means that our Sun distorts the fabric of space just like a...

Hello, In question 3(b) in the following file http://phstudy.technion.ac.il/~wn114101/hw/wn2010_hw09.pdf Why the orbit will be a straight line? I think that when the particles are coming to r=0 the potential will be infinity, isn't that so? So the energy will be infinity and e will be...

I've wanted to know this for 15 years. If every particle in the sun simultaneously tunneled to another galaxy, how long would it take the Earth to stop orbiting as if the sun were there? 0 seconds? ~7 minutes? Why? How fast does space-time un-deform?

I am having trouble understanding how stars orbit around a spiral galaxy. First off, my understanding of the Local Standard of Rest (LSR) is that it is a point which corresponds to the average velocity of all the stars in the defined local neighbourhood. This point moves around the centre of...

Can someone please help me with this? Epoch J2000.0 refers coordinate systems to the mean equinox and mean ecliptic of January 1, 2000, noon TT. I have the following mean orbital elements for Earth with element date January 1, 2000 and referred to j2000.0 epoch. a :=...

You launch an engine-less space capsule from the surface of the Earth and it travels into space until it experiences essentially zero gravitational force from the Earth. The initial speed of the capsule is 18,500 m/s. What is its final speed? Assume no significant gravitational influence from...

1. Homework Statement a spacecraft of mass 1000kg, in an elliptical orbit about the earth, at one point its distance from Earth is 1.2 x 107 meters and its velocity is 7.1 x 103 meters per sec, and the velocity vector is perpendicular to the line connecting the center of the Earth to the...

Homework Statement a spacecraft of mass 1000kg, in an elliptical orbit about the earth, at one point its distance from Earth is 1.2 x 107 meters and its velocity is 7.1 x 103 meters per sec, and the velocity vector is perpendicular to the line connecting the center of the Earth to the...

Hey there is one question I have that has been burning in my mind. I know that in elliptical orbits of satellites/ spacecraft s/planets around a planet, angular momentum and energy is conserved, but how do we find that angular momentum only knowing the velocity of the orbiting object, its mass...

"in 4-D, the Earth orbits around the sun in a straight line" someone told me that in 4-D, the Earth actually orbits around the sun in a straight line, could someone try to explain to me how this is so? thank you

The figure shows two planets of mass m orbiting a star of mass M. The planets are in the same orbit, with radius r, but are always at opposite ends of a diameter. This is the equation eq. I used: mv^2/r=GMm/r^2+Gmm/(2r)^2 This is what I came up with but it is not the right answer. Where...

What's the shape of the planets orbiting the sun in our solar system according to this website http://www.chacha.com/question/what-is-the-shape-of-orbit-of-planets they are elliptical. But in a documentary (maybe history channel's "The Universe", but I'm not sure) I heard that our solar system...

Why revolving bodies have their orbits elliptical and not perfectly circular (please correct me if I am wrong)?

I was recently studying elliptical orbits and the precession of the perihelion of Mercury. I remembered from my pre-calc class that all ellipses have two focal points. In this case the obvious would be the Sun as on focal point for all the planets, but where would the second be? I have a...

I was having trouble making sense of the geosynchronous orbits from a relativistic point of view. Correct me if I am wrong, but in a geosynchronous orbit the object appears to hover over a certain place on the Earth, from the point of view of the Earth, which can be said to be at rest according...

Homework Statement Mostly a bunch of extraneous information, so feel free to skim: Large stars can explode as they finish burning their nuclear fuel, causing a "supernova". The explosion blows away the outer layers of the star. According to Newton's third law, the forces that push the...

I'm just wondering if there is some sort of relationship between right coset and orbit of x. We just got to cosets, and it seems like the properties of cosets are eerily similar to orbits.

This question is of an elliptical orbit with v1 ant its distance r1 and a second v2 with distance r2 located a different point in the elliptical orbit Which general relation connects the speed vi of the satellite and its distance ri from the center of mass of the planet at any two arbitrary...

Hey all, Can someone please tell me why is the trace of the Jacobian of an integrable hamiltonian system equall to zero on the homoclinic / seperatrix orbit ? Cheers, Thrillhouse

So, the moon goes around the earth, the Earth orbits the sun etc... Are the orbits eventually decaying orbits? That is, given enough time, will the moon hit the earth, Earth go into the sun etc...?? Is that why galaxies are spiralling?

Does anyone know the inclination of each planetary orbit (in degrees) with respect to the plane of the Sun's equator-plane?All planetary inclinations are known with respest to the ecliptic, and the ecliptic's inclination is known with rescpect to the Sun's equator (7.25 degrees). Such data...

Hi Can someone explain why orbits are elliptical and not circular? Does elliptical orbits still follow the rules of circular motion (ex. constant centripetal force)? Thanks for any help that you can provide

This question came to me as having an obvious answer yet I don't know. If a human is floating in space they bend spacetime themselves and could technically have small stuff orbit them. Sorry for the dumb question; just been bothering me. thanks for any help

I was speaking with a friend about this today, I don't see a thread on it. http://www.msnbc.msn.com/id/32391095/ns/technology_and_science-space/

Hi all, I'm working on a problem where I have to find the time it takes for a planet to form from a protoplanetary disk, using the equation: t = \frac {3}{A}M^{1/3} Where A= ( \frac {(1+2\beta)\sigma}{P}) (\frac {3\pi^2}{4\rho_m})^{2/3} However, I'm not sure which units the...

I want to know the difference between the 2 types of rotations shown in the picture attached . planetary orbiting are similar to the second figure in the picture attached , all i want to know what is the difference between the 2 figures .

1-is electron orbit about the nucleus ? 2-is there is different between rotation and orbit? thanks in advance

Hello. I've read in many books that the orbits of the planets of our Solar system are ellipses. With the one Focus as the Sun. Well, what is the other one? I mean every ellipse has two focuses...

hi there we know that electrons around the nucleus in an atom can only exist in certain discrete energy levels (orbits) and that they can jump from one energy state to a higher one or a lower one. where is the electron when it is jumping from a higher stste to a lower state if it cannot exist...

This is nothing so involved as the actual mechanics of orbit. I'm just curious, is there a preferred plane that satellites orbit in? I ask because on my frequent stargazings, after my eyes are VERY well adjusted to the dark, I can see what I assume to be satellites moving pretty quickly across...

Homework Statement A 450kg satellite is to be placed at an altitude of 2.45 x 10^6m above the Earth surface. Calculate the period the satellite will have when orbiting at that altitude. Homework Equations m2g = Gm1m2/R^2 = m2v^2 = m2(4pie)^2 R /T^2 = m2 2pie v/T Ac=4pie ^2 R / T^2...

Hello, What is the difference between an unstable and an unbound orbit of a particle around a black hole? As far as I understand, an unbound orbit is (informally) a trajectory which does not represent a closed curve (such as an ellipse) around the black hole, and this condition formally...

given a Hamiltonian H=p^2 + V(x) how can you calculate the length of the closed orbits ? , i mean in gutzwiller formula you must perform a summation over the length of the closed orbits to calculate density of states g(E) but how can you know what the lenghts are ?? .. of course for Harmonic...

This is something I thought about while drifting off to bed last night. Immediately after the period between the big bang and the formation of planets, how did these newly created planets enter their respective orbits. I'm assuming the planets had different masses and that this was a...

exoplanets seem all to have elliptical orbits, and when you look at our solar system the orbits are all nice and defined, how come. And the gaz giants all seem to be star huggers where as in out solar system they are not, any explanations on this difference?

Homework Statement Comets travel around the sun in elliptical orbits with large eccentricities. Suppose the comet has an initial speed of 1.17*10^4 m/s when at a distance of 4.9*10^11 m from the center of the sun, what is its speed when at a distance of 5.9*10^10 m? Give your in m/s in...

Why doesn't the force of the sun's gravity, cause a drag on the Earth and cause it to slow down and fall into the sun? For, example, if I have a North Pole magnet, and project(throw) a South Pole magnet around it, no matter what speed and direction of my initial throw, will not cause the...

In a Keplerian orbit (an ellipse), the acceleration vector always points to the focus containing the central mass. Since that means the acceleration vector is no longer orthogonal to the orbit (except at two points), does the relation a = \frac{v^2}{r} still apply if we consider v to be the...

I have been told most of the planets around the sun have orbots elliptical in shape. I now understand that the orbits are formed due to 2 forces. i.e gravity of the parent body acting against the velocity of the orbitting body. The above only tells me that all orbitting objects should...