Orbit Definition and 1000 Threads

Gday all, I was just wondering if we would experience a (very small) centrifugal force due to the Earth's rotation around the sun or not. I don't think there would be because the Earth and everything on it is in a state of free fall around the sun, but I have been told there would be a...

Homework Statement (a) Derive an expression for the electron's speed in the nth Bohr model. (b) Prove that the orbit with highest speed is the n = 1 orbit,with v(1) = ke^2 / h compare this with the speed of light , and comment on the validity of ignoring relativity (as we did) in...

Tidal effects in the Earth-Moon system are causing the Moon's orbital period to increase at a current rate of about 35 ms per century. Assuming the Moon's orbit around the Earth is circular, to what rate of change in the Earth-Moon distance does this correspond? Hint: differentiate Kepler's...

Last chance to see Discovery in orbit! Discovery has separated from the ISS and they can be seen in early evening (great for kids) in much of Canada and the northern part of the US over the next few days. Go to this NASA site and punch in your country, state/province, and select a city near...

Homework Statement If there's a satellite(not man-made although I wonder it would matter) is chaotically orbiting around two planets, will it ever cross the same orbital path twice or not? Homework Equations The Attempt at a Solution I think if the system is chaotic, it will not...

I understand that an electron can gain and lose energy, but before this, the electron is spinning around the nucleus of an atom. Since motion requires energy, what is the energy that keeps the electron spinning. Further- since there is loss in every system- if no energy is applied or taken...

Homework Statement The gravitational field strength on the moon, which has a radius of 1.74 x 10^6 m, is approximately 0.17 as large as the gravitational field strength at the surface of the earth. The satellite is at an altitude of 100km above the moon. What is the radius of the orbit of...

in analysis of close binary stars, it is assumed that their orbits is circular and then by a rotating coordinate system, potential is obtained and then lagrangian points and so on... Is the orbit of CLOSE binary stars nearly circular in reality or is it assumed circular because otherwise it is...

Hi all, I have a gravitationally bound rubble pile asteroid. This asteroid reaches and exceeds 'critical' spin where centripetal force exceeds gravitational force and surface material is launched off the surface. At what minimum initial velocity would the surface material need to be to...

I was just wondering why, if the gravitational force exerted on it by the Sun is greater than the one exerted on it by the Earth, the Moon stays in orbit around the Earth? Is it due to angular momentum or are there any other factors?

Homework Statement Calculate the energy of a 100kg satellite associated with a geostationary orbit around a planet. Homework Equations Kepler's 3rd Law: T^{2} = \left( \frac{4 \pi^{2}}{GM_{p}} \right)r^{3} Velocity equation: v = \sqrt{\frac{GM_{p}}{r}} Planet mass: M_{p}...

I've read on PF that you can't shoot something, like from a big gun, into Earth orbit; it will either fall back to Earth or attain escape velocity and be gone forever. Instead, you need a separate rocket burn to insert the object into orbit following launch. Makes good sense to me. So we are...

I have been doing some study on the theory of relativity and it has got me thinking. We say that the Earth revolves around the Sun but from what reference frame? From the reference frame of Earch, we are stationery and the Sun simply spins. Why is any reference frame more accurate than another...

Homework Statement Suppose that a satellite is in a circular orbit at a height of 2.00x10^6 m above Earth's surface. What is the tangential speed of a satellite in this orbit? Homework Equations vt=rw The Attempt at a Solution I have been stuck for almsot 30 minutes, I think that...

I have been searching the internet for the last few days with no luck, due probably to the improper phrasing of my searches, for what I think is a fairly straight forward set of answers. Basic Question: "Are there equations to graph the orbits of our solar system's planetary bodies on to a...

Homework Statement I have been able to complete section a and b but c doesn't match the answer a)The acceleration of free fall at the surface of a planet is g and the radius of the planet is R. Deduce that the period of a satellite in a very low orbit is given by T=2pi sqrt(R/g). b)Given...

Hey guys, I did some basic research on the transfer orbit to Mars. It turns out that Hohmann Transfer Orbit is the most fuel efficient. What I really want to know is that if there is any other type of transfer orbit proven valid that is the quickest. Really appreciate your help!

Homework Statement A positively charged Helium atom has two protons in the nucleus and one electron in the shell, in a classic model of the atom, this electron is in a circular orbit around the nucleus with an angular momentum of 4.718x10^-34 Js. What is the radius of the orbit?Homework...

Homework Statement NASA would like to place a satellite in orbit around the moon such that the satellite always remains in the same position over the lunar surface. What is the satellite's altitude? Homework Equations T^{2} = \left(\frac{4\pi^{2}}{GM}\right)r^{3} The Attempt at a...

Homework Statement (a) In terms of energy expenditure: 1. Which planet in the solar system is easiest to reach? 2. Which major body in the solar system is hardest to reach? Why, and what shape orbit would be needed to get there? 3. Which of the following scenarios requires more...

It certainly seems like it. People are far more excited about Titan than they are about Saturn. And the same is true for several other Saturnian moons. Same with Jupiter and its 4 biggest moons. People seem to care more about its 4 moons than Jupiter itself. I'm no exception. But certainly, I...

You know how orbits are made of ellipses and ellipses are made out of two foci? I'm trying to find a formula where I can extract the position of the other focus point, relative to (0,0). By the other focus point I mean the one that's generally out in space. Very much like how the...

Homework Statement A Hohmann transfer orbit is a way of transferring a spacecraft between two planetary orbits (which we shall assume are circular) by using one half of an elliptical orbit about the Sun. A spacecraft is initially moving around the Sun with the orbital speed V1 of the...

Homework Statement A satellite is in a circular, geosynchronous orbit (makes one revolution around Earth in 24 hours). Calculate the distance in meters from the satellite to the Earth's center. Mass of Earth = 5.97 x 1024 kg Homework Equations T=((2*Pi)*r^(3/2))/sqrt(GM) The...

Good day to all :wink: I would like to find out the amount of man-made objects rotating around the Earth at high altitudes, more precisely beyond the geostationary orbit, for example at the altitude of 45 000/50 000/60 000 km above the sea level. Are there any data available for this purpose? I...

Homework Statement If given a speed of a spacecraft , and a radius from the sun, how do you prove that it was or was not in a circular orbit about the sun? Homework Equations The Attempt at a Solution To prove it is not do I just find the mass of the spacecraft and the size of...

The problem I am struggling with is this . . The centre of the Earth-Moon system is 4.7x10^3 km from the centre of the earth. Calculate; i.the ratio of the mass of the Earth with the mass of the moon. ii.The acceleration of free fall on the Moon's surface. Constants Distance between...

Homework Statement Determine how much energy is needed to move a satellite of mass 500kg to an orbit of height equal to Earth's radius.Homework Equations Gravitational Potential: V = \frac{-GMm}{R} Where M is the mass of Earth (6*10^24kg), m is the mass of the satellite (500kg) and R is the...

Homework Statement At its perihelion in February 1986, Comet Halley was 8.79x10^7 km form the Sun and was moving at 54.6 km/s. What was its speed when it crossed Neptune's orbit in 2006? Homework Equations K0+U0=K+U The Attempt at a Solution I know I need to do this using...

If most of the universe falls into a massive black hole, will it be possible for the Earth to be kept away from it, for example by going into orbit of the black hole? In this situation, the Earth would be the last remaining matter outside of the black hole as everything else in the entire...

Homework Statement http://www.its.caltech.edu/~tmu/ph1a/FPs/fp12.htm this is the question. Homework Equations T^2=\frac{4\pi^2a^3}{GM} E=-\frac{GMm}{2a} The Attempt at a Solution I have none. My question is, does the fact that there are two planets affect the equations for period and...

Homework Statement A 2580-kg spacecraft is in a circular orbit a distance 1580km above the surface of Mars. How much work must the spacecraft engines perform to move the spacecraft to a circular orbit that is 4190km above the surface?Homework Equations \DeltaU=GMsMm(1/r_2-1/r_1)...

Homework Statement (a) What is the minimum speed, relative to the Sun, necessary for a spacecraft to escape the solar system if it starts at the Earth's orbit? Homework Equations Kinetic Energy=Potential Energy 0.5mv^2=rGM/(r^2) 0.5v^2=GM/r Where M is the mass of the sun, and r is the...

Hi guys! I am really involved in a scientific project. I have to put in orbit an object. I was wondering what formulas I could use..? I know pretty well kepler's laws, which are very helpful, but I don't know how to put in orbit an object... ? I can easily calculate its tangential velocity and...

This is obviously a highly complex question, but I'm really interested in it, and I still don't know where to start after looking around a while. If you had an object that was .019 kilograms, how fast and at what angle would you have to shoot the object at to get it to orbit at 200000 meters...

Homework Statement Find eccentricity for: a comet with mass 1.2x1010kg moves in an elliptical orbit around the sun. Its distance from the Sun ranges between .5AU and 50 AU. Homework Equations The Attempt at a Solution I drew it out to try and viualize it and i know eccentricity...

Problems with an Orbit... Homework Statement what is peculiar about the orbit" Semimajor axis = 5740km Eccentricity = 0.1 Inclination = 53 Right ascension of the ascending node = 345 Argument of perigee = 270 True anomaly = 183 Homework Equations The Attempt at a Solution...

Homework Statement A. Suppose you are at the Earth's equator and observe a satellite passing directly overhead and moving from west to east in the sky. Exactly 15.0 hours later, you again observe this satellite to be directly overhead. How far above the Earth's surface is the satellite's...

Homework Statement Suppose a spacecraft of speed v_c is in a circular orbit around the Earth at a height H from the surface of the earth. The rocket motor is fired in the opposite direction of motion to reduce the satellite's speed to v_0 and make the orbit elliptical. Let R denote the...

I am kind of new to astronomy and I have a few questions.. I need to be able to determine an equation expressing the elliptical orbit of Oberon around Uranus. I have four nights of data showing Oberon in different positions relative to Uranus. I am able to calculate the RA and Dec for both...

Homework Statement Given: G = 6.67259 × 10−11 Nm2/kg2 The acceleration of gravity on the surface of a planet of radius R = 4190 km is 6.5 m/s2. What is the period T of a satellite in circu- lar orbit h = 14120.3 km above the surface? Answer in units of s. Homework Equations...

We stay in orbit around the sun? Our own planet's kinetic energy keeps it from succumbing to the Sun's gravity, same concept with the electrons, this time Gravity being electromagnetic force right? Edit: Damnit, wrong section...

First post, I am just a layman, so go easy. The way I understand it, the moon is following a straight line through space. However, the mass of the Earth is so great that it warps the fabric of spacetime and it appears that the moon is going around the earth. Same with any moon or planet, they...

Why Earth's orbit is elliptical rather than being perfectly circular

If G is a permutation group acting on a finite set A and x \inA, then |G| = |\Delta(x)| |Gx| where \Delta(x) denotes the orbit containing x. I'm having some difficulty understanding this theorem. For example, Consider the following set G of permutations of the set M = {1,2,3,4}...

Is the Moon’s orbit more or less elliptical than the Earth’s? How does this affect the range of angular sizes for the Moon vs. the Sun? I always thought smaller objects are less elliptical than larger objets, so the moon would be less elliptical Can someone clarify? Thanks!

Of course Earth's orbit is not circular, but Is Earth’s orbit far from circular? Thanks

In certain cases, using both the momentum principle and energy principle to analyze a system is useful, as they each can reveal different information. You will use the both momentum principle and the energy principle in this problem. A satellite of mass 4000 kg orbits the Earth in a circular...

Homework Statement A 62kg satellite orbits the Earth with a radius of 3.3*10^7 m. A net external force acts on the satellite to an orbit of 7.7*10^6 m, what work must the external force do? Homework Equations W = integral of F with respect to d The Attempt at a Solution Integrate...

How do you calculate the distance above the surface of the Earth to geosynchronous orbit.