Orbit Definition and 1000 Threads

Homework Statement On which orbit of hydrogen atom an electron has the speed of 734 km/s? Homework Equations Bohr's second postulate: mvr=nh,m=9.109\cdot 10^{-31}kg,v=734 km/s,h=6.626\cdot 10^{-34} m^{2}kg/s The Attempt at a Solution By using the second Bohr's postulate, we get 6686.006\cdot...

Imagine thee planets interacting through gravity, mathematically how should they come and rotate in a same plane, like planets and sun?

I finally found a result I believe for the the asymptotic metric (valid for large r) of a pair of bodies in a circular orbit emitting gravitational waves. I use spherical coordinates, ##[t, r, \theta, \phi]##. If we let the linearized metric ##g_{\mu\nu}## be equal to the sum of a flat metric...

Homework Statement A satellite moving in a highly elliptical orbit is given a retarded force concentrated at its perigee. This is modeled as an impulse I. By considering changes in energy and angular momentum, find the changes in a (semi major axis) and l (semi latus rectum). Show that \delta...

Hello, was just wondering, what determines the gravitational orbit of an object orbitting a planet, for example, Saturn. Would increasing the size of the object decrease the distance between the object and the planet? Also, what determines the speed at which anything moves throughout it`s...

I read the Jupiter is so big that it doesn't really orbit the sun. Is that true?

If the orbit of the Earth has only one focus which is the Sun then why can't it move in a circular path. Since a circle has only one focus and that is at the centre. Why is the sun the only focus when the path of Earth is an ellipse?

Homework Statement The potential energy of a particle of mass m is V(r) = k/r + c/3r^3 where k<0 and c is a small constant. Find the angular velocity \omega in a circular orbit of radius a and the angular frequency \omega' of small radial oscillations about this circular orbit. Hence show...

Homework Statement This question involves parts of other questions, so I will state the relevant parts and essentially what the question is asking. It is from Kibble Classical Mechanics, Chapter 4, Question 22. If more information is needed I will provide. We have a satellite that orbits the...

If a planet is in retrograde orbit, what direction would it rotate to also have retrograde rotation?

Homework Statement A satellite is in a circular orbit very close to the surface of a spherical planet. The period of the orbit is 2.53 hours. What is the density of the planet? Assume that the planet has a uniform density. Homework Equations T^2=(4pi^2r^3)/GM V=4/3piR^3 Density= Mass/...

Homework Statement Say I have some planet in a circular orbit around a star, and I give it a small radial push (directly toward or directly away from the star). How would I describe the new orbit? I.e. how would I determine the equations of motion? h Homework Equations Kepler orbital radius...

Wasn't sure exactly what the title of this post should be. Working on a side project using machine learning and the solar system (using n-body simulator). Let's say I have two bodies with coordinates: Body1: x=-1.42790218981 y=1.4003882805 z=0.0 Body2: x=0.983274588755 y=0.0477301860159 z=0.0...

Do all electrons orbit in the ground state, when the band gap, is increased, or decreased, as atoms come together to form molecules.? Like in glass, transparent liquids, and plastics. As atoms come together to form glass, like silicon, sodium, and calcium. Do the electrons orbital permanently...

Homework Statement Two masses, M and m, are initially (at time t=0) at rest with respect to each other and separated by a distance d. They are affected only by their mutual gravitational attraction. Find the amount of time elapsed beginning at the instant the separation is equal to d/2 and...

Hi guys, I've recently been reading a lot of Jules Verne and I had a few curiosities that you guys could help with. First, if we were to shoot or fling a bullet to low Earth orbit, what would the muzzle velocity have to be?? Second, instead of a bullet, if we used a capsule with one passenger...

There have been many questions on this forum about celestial mechanics in general, and concerning position and velocity in an orbit in particular. So I offer this post as a summary and reference. Here's a method for finding heliocentric position and sun-relative velocity in ecliptic coordinates...

I am stuck at this part page 1, $$\frac{\partial{L}}{\partial{\dot{φ}}}=\mu{r^2}\dot{φ}=const=l------->\dot{φ}=\frac{l}{\mu{r^2}}......(8)$$ Why is this a constant? Isn't r and dφ/dt variables of time? Source: http://www.pha.jhu.edu/~kknizhni/Mechanics/Derivation_of_Planetary_Orbit_Equation.pdf

I understand the difference between comets, asteroids, and meteoroids. I was just reading about asteroids recently, and it occurred to me that when I read anything about these three types of objects the implicit (and sometime explicit) assumption is that they only apply to things that orbit the...

Homework Statement Compute the escape velocity for a projectile fired from the surface of the moon. The moon’s radius is 1700 km, and its surface gravity is ##1.62 m s^(−2)## . Neglect the effect of the Earth. A second projectile is fired horizontally from the lunar surface with a velocity f...

Homework Statement Sputnik I was launched into orbit around Earth in 1957. It had a perigee (the closest approach to Earth, measured from Earth's center) of 6.81 × 106 m and an apogee (the furthest point from Earth's center) of 7.53 × 106 m. What was its speed when it was at its perigee? The...

Homework Statement A satellite with mass 848 kg is in a circular orbit with an orbital speed of 9640 m/s around the earth. What is the new orbital speed after friction from the earth’s upper atmosphere has done -7.50·109 J of work on the satellite? Does the speed increase or decrease? Homework...

http://physics.ucr.edu/~wudka/Physics7/Notes_www/node98.html In the link given below, it is explained how general relativity predicts the correct results. However I am curious about the answer of the following hypothetical scenario. Let us assume that we replaced gravity with the...

Homework Statement A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth. Choose the correct statement. Ans: (A) the acceleration of S is always directed towards the centre of the earth Homework Equations F=...

Consider a stable circular orbit (with a central force) subjected to small perturbations. The orbit equation is given by (3.45). The text argues that the ##\beta## in (3.46) must be a constant over the domain of ##r_0##: "Otherwise, since ##\beta## can take on only discrete rational values (for...

Homework Statement (Assuming all circular orbits) [/B] Say there is a star with mass M and a planet orbiting that star with a mass m. The star M then suddenly loses half of its mass. (So now it is M/2) What is the new radius of orbit of the planet around the star? Warning: Velocity will not...

Homework Statement we know the mass of the moon, Mm, and the Earth's, Me, and also the initial distance between their centers as the moon orbits the earth, Rem. Now if the earth’s angular velocity about its own axis is slowing down from a initial given angular velocity, ωi to a final angular...

Homework Statement Okay, so the question seems really simple so I don't know what I'm missing A satellite orbits at a fixed point above the Earth's equator. Assuming the Earth has uniform density, radius R, and angular frequency of rotation, omega Find an expression for eta, such that the...

This pertains to a homework question but I get the concept of PE or U = -GmM/a for an elliptical orbit. I also understand the derivation of the total energy of an object in an elliptical orbit as E = -GmM/2a. However, I have a homework question that asks for the ratio of an object's kinetic...

Homework Statement What fraction of its "year" (i.e. the period of its orbit) does a planet spend traversing the half of its orbit closest to the sun? Give the answer in terms of the eccentricity ε of the planet's orbit. This is problem 15 from page 852 of Adam's Calculus 3ed. No detailed...

The problem is as follows. "NASA places communication satellites into Earth orbit with a radius of 42000 km. If the centripetal acceleration of one of the satellite is 0.22m/s^2, how long, in hours, will it take this satellite to make one complete orbit? For this chapter, these are the...

I was wondering, since gravitational atttraction is determinated by m1 * m2 / d2 * G , can an object have a mass too little to have a stable orbit, for instance, around the sun? P.S: I'm new to this forum! Hello!

So let's say you are on an orbital satellite in an elliptical orbit around our planet Earth, meaning that the at one point in the orbit you are going faster, due to the gravitational pull of the planet. Would you feel the acceleration in space due to the shape of the orbit?

I have a real doosy that has got me stumped. I need to solve the following equation for v: tan(v + ω) = tan(θ + Ω)sec(i) The symbols stand for the following values in an elliptical orbit of one point source around another (on the celestial sphere): where v = true anomaly; ω = argument of...

Homework Statement A force field in 2-d F~ = −kr(rˆ) with U(r) = k(r^2)/2 acts on a particle of mass m. The particle is now in a non-circular orbit. In terms of the particle’s angular momentum L and energy E, d) What is its closest approach to the origin? e) What is its furthest distance from...

There are two examples: A planet rotating around a star and a spacecraft maneuvering through space. Let's assume that solar radiation has no affect on the spacecraft and the spacecraft is not bumping into any stuff, and niether is the planet; and no other gravitational sources are involved...

Hi, So apparently electrons don't orbit the nucleus of atoms so I'm assuming the lack of movement means that no energy from the atom is radiated away from an atom due to minuscule gravitational waves, over the life of the universe. But gravitational waves have got me thinking about reference...

I kind of understand how orbit works. So an object falls 10 feet then the Earth's curve counteracts the 10 feet, so it's prevents the object from just crashing down to earth. But wouldn't the object slowly either come closer to Earth or go away from earth. As in like millimeter by milimeter.

Is there an accurate method in computing the 'sound' frquency of a planet? For example, taking the orbital path of say Jupiter for one year, and computing it into an audible frequency? I'm looking for ways to compute this, but I am at a loss to where the best starting point is. Could Bohr's or...

I understand that if there is a body in a circular orbit around the Earth (or any other thing), and there is an impulse directed radially out away from the Earth against the orbiting body, the body will end up in an elliptical orbit, which will pass through the original circular orbit. This got...

Hi All, Having difficultly figuring out where I've gone wrong with this problem. Any guidance gratefully received. 1. Homework Statement A 4.76 keV electron (an electron that has a kinetic energy equal to 4.76 keV) moves in a circular orbit that is perpendicular to a magnetic field of 0.392...

What is the underlying feature of general relativity that, unlike Newtonian mechanics, results in the correct calculation of orbits i.e. including precession (e.g. Mercury). I not asking for the mathematics (i.e. the additional term in the equation) but rather what underlying "physical"...

So, I have really no background in astrophysics (other than touching on some areas in general physics and calculus). I understand that asking questions such as the one in my title, that I would need to be more specific, and I will attempt to be as specific as I can. I understand that most...

If you haven't seen this video before then go watch it :D Question: Answer: It is pretty hard to imagine it as a spring and here is why: 1) At (o) the spring should move by its inertia not by any force. If we look at the planet we can summarize that there are 2 points (As I think) that could...

Hi all, So the (hypothetical) question I have is about the range of the Earth's length of orbit (number of days) within the Sun's habitable zone which could sustain human life. I.e. what would the length of the shortest 'habitable' year be, and the longest (in days)? What would our living...

Hello, I'm working on a hypothetical situation involving a planetary body orbiting a black hole (similar to the scenario in Interstellar, but for different reasons), trying to balance tidal forces with orbital distance and time dilation. First, I'm interested in the effect of gravitational...

Could the orbit filling order of electrons be more classical and less quantum? I attached a jpeg and need someone to do a electrostatics analysis of the CAD model version of it. Does anyone have an electrostatics software package and have time to do a finite element analysis on a 3-D part to...

Hi. Now that I understand the conservation law of angular momentum, and given the fact that c is constant, I infer that if a photon were to go into orbit around a black hole, it could only take a circular orbit. No elliptical orbits for photons, because if it were to follow an elliptical orbit...

Homework Statement THe sun has a mass of 1.99x10*30 kg. Jupiter has a mass of 1.90x10*27 kg and a mean radius of orbit around the sun of 7.78x10*8 km what is the speed that Jupiter travels in its orbit around the sun? Homework Equations fg=(Gm1m2)/d*2 fc=(4pie*2mr)/T*2 The Attempt at a...

Lets assume you could fire a 100kg projectile using a coilgun at 1 degree above the horizon and have it arrive safely at 400km altitude traveling at 7.8km/s (or slightly more if that helps). How much delta-v would it need to correct its trajectory into a stable orbit? If it matters let's...