Orbit Definition and 1000 Threads

Homework Statement A 5530-kg satellite is in a circular Earth orbit that has a radius of 1.81 × 10^7 m. A net external force must act on the satellite to make it change to a circular orbit that has a radius of 8.01 × 10^6 m. What work must the net external force do? Homework Equations...

Homework Statement A spacecraft moves in a circular orbit with a speed of 7.60E+0 km/s with a period of 95.1 min. What is the radius of the spacecraft 's orbit? My answer, which is correct, is 6.90×106 m What is the radial acceleration of the satellite? 8.37 m/s^2 was my answer, and it...

How to simulate planets orbit curve around the sun ? Hi I'm about to write a java program where I wish to simulate planets orbit curve around the sun, so that I can set the speed of a planet and mass of planet and sun and simulate the curves around the sun (just basic simulations). I only...

Homework Statement When it orbited the Moon, the Apollo 11 spacecraft ’s mass was 7170 kg, its period was 121 min, and its mean distance from the Moon’s center was 1.87167 × 106 m. Assume its orbit was circular and the Moon to be a uniform sphere of mass 7.36 ×1022 kg. Its orbital speed was...

Homework Statement Suppose that Captain Omega of the Imperial Space Patrol wishes to place a spy satellite in geosynchronous orbit above the mysterious Planet X, which has a mass of 5.90 x1024 kg, and a rotational period of 26.4 hours. (a) What should be the radius of the satellite's orbit...

Hi, I am curious whether that when the Earth is in its closest position to the Sun, the Suns gravitational pull has a direct effect on the Earths orbital speed. Since the speed of an object has an effect on time. Would the increase in speed affect time in general. Of course the time is...

If two bodies are moving about a common point, with one orbiting the other, in a completely circular orbit, from knowing just their periods (which are equal) and the graviational constants of each body times mass, how would you determine the radius of each of their circular orbits? You can get...

when electrons are in their standard orbits , why is it that they don't absorb or radiate energy ??

For a satellite in circular orbit above earth, state how the following properties depend on radius? a) period b) kinetic energy c) speed This is the question i need help with folks... I've answered it using words so far (correct me if I'm wrong) but I'm wondering how i could go about this...

Homework Statement The most energy-efficient method of getting a spaceship from one planet to another is via a Hohmann (transfer) orbit. The ship's launch is aimed in such a way that the perihelion and aphelion of the ship's orbit is tangent to the circular orbits of the two planets and timed...

Hello everyone! Should be obvious it's my first time here. I'm looking for assistance not for myself, but for my girlfriend. She's got a college science class that up until now I was able to help her with, but unfortunately my physics knowledge (one year in high school, eight years ago now) did...

[Solved] Proton orbit direction Homework Statement A solenoid has a magnetic field in the +z direction. A proton in the center of the solenoid moves towards the sides sides of the solenoid. Will this proton move with a clockwise or counterclockwise motion? Homework Equations F = qv x...

Relative some arbitrary point in Earth’s orbit around the Sun, does Earth experience varying degrees of time dilation specifically from gravity? With Earth's orbit around the sun being elliptical I wondered if Earth experiences varying degrees of time dilation caused by the suns gravity (or...

Homework Statement There is no general analytical solution for the motion of a three-body gravitational system. However, there do exist analytical solutions for very special initial conditions. The figure below (see attachment) shows three stars, each of mass m, which move in a two-dimensional...

Homework Statement Distance from Earth to sun = 1.50 * 1011m Earth's orbital period = 3.16 * 107 s Distance from venus to sun = 1.08 * 1011m Venus's orbital period = 1.94 * 107 s Both orbits around the sun are coplanar, and the transit of venus about the sun is observed by a telescope on...

Scientists want to place a 2500 kg satellite in orbit around Mars. They plan to have the satellite orbit a distance equal to 1.8 times the radius of Mars above the surface of the planet. Here is some information that will help solve this problem: mmars = 6.4191 x 1023 kg rmars = 3.397 x 106...

"Flyaround" video of Vesta as seen from low orbit by Dawn http://science.nasa.gov/science-news/science-at-nasa/2011/16sep_vestaflyaround/

Why does the moon's orbit move from low in the sky to higher in the sky, then back? I have tried accessing information on precession, etc. with no understandable answer. Wikipedia was no help. It's a minor issue, but one that has left me scratching for a long time.

Hi everyone, I am trying to implement in Matlab a particle filter to perform the orbit determination of a spacecraft . I think my problem is the way I do the particle resampling. As you can see in the code I already tried to: - scale the measurement difference (true - predicted) in order to...

Homework Statement Prove that the following system has at least one periodic orbit. x' = x - y - 2x3 - 2xy2 + x2sqrt(x2 + y2) y' = x + y - 2x2y - 2y3 + xysqrt(x2 + y2) Homework Equations The Attempt at a Solution I converted to polar coordinates to get r' = (xx'+yy')/r and...

I get different result than stated in the book. What am I doing wrong? Homework Statement A spacecraft returning from a lunar mission approaches Earth on a hyperbolic trajectory. At its closest approach A it is at an altitude of 5000 km, traveling at 10 km/s. At A retrorockets are fired to...

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. These are called geosynchronous orbits. The altitude of a geosynchronous orbit is 3.58*10^7 m. What is the apparent weight of a 2000...

Can an antiproton(negatron) "orbit" around a regular nucleus? Since it's negatively charged like an electron, can it orbit around a "normal" nucleus? Or a more general question: can something be part matter and part anti-matter? Edit: I guess this answers my question...

Hi guys, i can't seem to find the answer . A satellite in Earth orbit has a perigee velocity of 8 km=s and period of 2 hours. From this information, determine all the orbit parameters that you can. From those parameters, determine its altitude at perigee...

This was an idea I had when when learning about ramjets. I was wondering if you could use a specially designed rail gun to launch a probe or satelitte ,at a very high velocity vertically upwards and then when the object is decelarating at 9.8 m/s due to gravity use a small rocket propulsion...

Homework Statement If a satellite in orbit changes it's orbiting radius to 4 times its initial one, how does it's velocity change? I get different answers by using Newton's Law of gravitation and conservation of angular momentum. Homework Equations F = \frac{G M m}{R^2} a_c =...

the answer for a is .571 rad/s for b, I am not sure do i use like kinematics?? and I am lost on c? If feel a is velocity = distance/time so is it 2pi*3040/60? and not sure on b either.Sorry these are a lot of questions, but i am trying to learn and get an A, so i want to make sure I get all of...

Greetings I have been trying to find the orbit of Mercury using the geodesic equations with the Schwarzschild Metric, more precisely I have been using the equations derived in "General Relativity, An Introduction for Physicists" by M.P. Hobson, etc, that is: <math>\left(1-\frac{2\mu}{r}\right)...

Homework Statement A rocket is in an elliptical orbit around the earth; the radius varies between 1.12 Rearth and 1.24 Rearth. To put the rocket into an escape orbit, its engine is fired briefly in the direction tangent to the orbit when the rocket is at perigee, changing the rocket's velocity...

Backward "orbit" of the planets How do you tell when a planet is going backwards in its "orbit" of the earth? Do you have to plot a graph and pick out the points? There must be an easier way!

To explain weightlessness to my students, I use the analogy of a falling elevator (lift) as folows - if we stand on weighing scales in an elevator and the elevator cable snaps, the scales will show zero since they are falling to the ground at the same acceleration as us, therefore registering no...

I'd like to share with you people this great discovery! http://arxiv.org/abs/1107.2389 A 12 minute Orbital Period Detached White Dwarf Eclipsing Binary Warren R. Brown (1), Mukremin Kilic (1), J. J. Hermes (2), Carlos Allende Prieto (3), Scott J. Kenyon (1), D. E. Winget (2) ((1) SAO...

Hi all, If one were to consider a classical particle in a box of length L in Minkowski space then clearly the time taken to go between the walls of the box is L/v with v velocity. In the GR case with some metric coefficients A(r) and B(r) (spherically symmetric system, say) it's clear that...

Dawn spacecraft is nearing Vesta and is planned to go into orbit 16 July. http://science.nasa.gov/science-news/science-at-nasa/2011/06jul_vestamoon/ The craft will orbit Vesta for several months and then move on to another asteroid, Ceres. The NASA press release mentions that several...

Hello PF. I learned, for some time ago, that objects in space in orbit are weightless and to this day it still blows my mind. Its rumored that Issac Newton sat under the apple tree and in the same view he saw that apple drop from the tree to the ground he also noticed the moon up in space and...

Hey folks I'm looking into halo orbits and I have a question about how to find the initial conditions from the third order approximation solution... A good run through of the third order solution calculation is found in this paper...

Good morning, I've searched about this case in the internet but just found things about asteriods sharing the same orbit as Earth over the sun, but I wonder if an asteroid can get stuck in Earth's orbit like the moon. Thanks!

I was wondering... Suppose that the mass that was being orbited, in place of the earth, was stable and constant - then substitute the moon with another constant but suppose the orbit is the same as the mass and distances between them are the same - would/could this be an example of perpetual motion?

How did Kepler knew that the time of Mars' orbit was 687 days ? It doesn't seem to me a simple task to determine that timing because after 687 days, Earth is at a different place in the solar system and Mars seems to be also in a different place in the solar system. How was that 687 days...

Homework Statement At teh Earth's surface, the curvature is such that if you traveled in a straight line at a tangent to the surface of the Earth for 8kms the Earth would drop away 5 m. How fast would you need to travel to be in orbit at the Earth's surface? (radious of the Earth...

Hello! I don't know if this is in the right place or not. So if it's not, I won't misplace it in the future. Anyway, I was recently thinking about the orbits of planets around Binary Stars, and was wondering if it's possible to have a similar orbit around the Earth and the Moon. Have a...

Hi. I am trying to find the classical turning points in semi-parabolic coordinates for the hydrogen atom when an electric field is being applied to it in the y-axis. I am reading an article for those who are interested called Classical, semiclassical, and quantum dynamics in the lithium...

Hi all, Im new here so please be gentle. Whilst in the pub last night a game was started with spinning a coin. We got to the point where we could all spin the coin with our hands in a circle around the salt shaker, about 3cm diameter. We then moved on to the pint glass and achieved that...

Interesting news about planets with no orbit: http://news.yahoo.com/s/ap/20110518/ap_on_sc/us_sci_wandering_planets Perhaps enough mass to explain dark matter?

According to Einstein's theory of general relativity, light bends--or rather space bends--around mass. So, in theory, is it possible for a photon to orbit around a body of sufficiently large mass?

Hello, I would like to ask why if the Earth rotate around the Sun in circle orbit, it must have an kinetic energy equal to negative half of potential energy it has at anytime rotating round the sun, which Ek = -Ep/2 ! If this situation cannot be achieved, our Earth will move in a new ellipse...

The question is... A satellite is in a circular orbit about the Earth (M = 5.98 x 1024 kg). The period of the satellite is 6.72 x 104 s. What is the speed at which the satellite travels? I know the speed is equal to (2piR)/6.72x10^4s But I can't figure out the radius. I know the Earth's...

Theoretically how much potassium nitrate would you need to get a 10 kg rocket out of the atmosphere and orbit as at the moment me and a group of highly intelligent freinds are working on a rocket to get out of orbit to prove a point to the man ect ect... and we need help

Homework Statement Two satellites are in circular orbits around Jupiter. One, with orbital radius r, makes one revolution every 16 h. The other satellite has orbital radius 4.0r. How long does the second satellite take to make one revolution around Jupiter? A. 130 hours B. 120 h C. 140 h D...

This is my first question here, so I'm a little new at this. I've really learned a lot from this forum in the past. Here goes: 1. Suppose you are responsible for a no-engine rocket project which carries a new satellite into space a. What is the the minimum initial speed of the rocket to...