Orbit Definition and 1000 Threads

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...

The book argues that since substituting ##\theta## by ##-\theta## leaves the orbit equation (3.34) unchanged, the orbit is therefore invariant under reflection about the apsidal vectors (Fig 3.12). If substituting ##\theta## by ##-\theta## leaves the orbit equation (3.34) unchanged, then there...

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...

Hi, I've read that SOHO (SOlar and Heliospheric Observatory) is orbiting around the L1 point. I remember this point being unstable (that is, that something in orbit will diverge from stability). How are the corrections made for this orbit ? Does it really cost a tiny amount of fuel, or is the...

I want to create a simple 2d Gravity simulator where I have a large body i.e. A circle which could be a planet or the sun. I then want to simulate small comets or asteroids traveling past it, crashing into or being pulled into orbit. I know the gravitational force formula but that seems the...

Assume that these orbital elements remain good for Vesta and for Ceres in the year 2080. Vesta. a = 2.3617272 AU e = 0.08889958 i = 7.14° Ω = 103.8467° ω = 151.1467° T = 2456923.543 Ceres. a = 2.7680973 AU e = 0.07575951 i = 10.5917° Ω = 80.3229° ω = 72.7187° T = 2456552.887...

Homework Statement http://prntscr.com/9huihp Given, Mass of the Earth = 6*1024 Mass of Satellite = 45 kg Radius of Satellite's orbit = 4.2*107 G = 6.67*10-11 Find the velocity of the satellite. Homework Equations Gravitational Force Fg = (G*Me*Ms)/(Rs2) Newton's second law: Fg = Ms*a where a...

A great launch, everything worked as expected, delivering 11 OrbComm satellites to Earth orbit (they all got deployed in the minutes after reaching orbit). But that was the routine part... although it was the first flight of an improved version of Falcon 9 1.1 ("Full thrust" version). The first...

Homework Statement I have been tasked with showing "how the mechanical energy of a planet determines the shape of its orbit", and I cannot for the life of me make sense of it. I've run into a formula, see below, but I'm not sure how to interpret it nor if it even applies in my case at all (as E...

What is the physics behind a orbit a cube planet. Does the convential physics including keplars laws and circular motion still apply. Also The cube having a centre of mass posited in the middle of the cude does this mean it can be consider point mass and the same as spherical planet orbit? any...

Hello, I have this problem statement : "Due to air drag, the radius of a satellite’s circular orbit decreases from r to r - △r, where the positive quantity △r is much less than r. The mass of the satellite is m. Show that the increase in orbital speed is △v = +(△r/2)[(GM/r^3)^1/2]; that the...

Hey, how's it going! Just a little confused about how to do the problem below. Any help would be appreciated! 1. Homework Statement A satellite of mass m=100,000 kg is moving around the Earth in a circular orbit at an altitude of 100,000 feet above the surface. If the satellite were stopped and...

An ellipse has two foci. For a planet in such an orbit, the star is at one of the foci. The other is empty. According to Ptolemy, if we draw a line connecting the planet and the empty focus, we will find that the line moves at a constant angular velocity. Is this true, or is it a crude...

1. Which will have the greater force during impact; a bumble bee being hit by a train or a train being hit by a bumble bee? (Hint: Newton’s Three Laws of Motion) 1. What is the centripetal force that holds the Earth in orbit around the sun? 1. How much does a 76.0 kg person weigh on Earth in...

Two satellites A and B move around Earth in a circular orbit. The mass of B is twice the mass of A then I agree that kinetic energy of B is greater than that of A. But what I couldn't understand was that why are speeds of A and B equal as given in the book. Shouldn't they differ according to the...

If we provide a satellite with escape velocity perpendicular to the earth(radially), would it start orbiting it?

Hi PF I've beent rying to model the lunar orbit around the sun (cardioide) as a parametric function, but have run into a problem. f(t) = r(t) : x = a cos(ωt) y = b sin(ωt) z = k t The angular frequency ω as well as the distance from to the center varies around the orbit. Is...

Homework Statement What is the time of an orbit of a satellite around the moon close to the moon's surface? What quantities do you have to look up to be able to answer this question? Radius of moon is 1736482 meters Homework Equations F = Gm1m2/r^2 and maybe F=mv^2/r 2pir The Attempt at a...

Dear All, Is it possible to watch Earth orbiting the sun in space like we watch a car coming towards us on a highway ? I mean, I would like to see it coming towards my spaceship at the rate of say 50 km/hr. Now some questions - 1. What should be my location and speed of my spacecraft...

Most threads about making orbit changes assume impulsive changes in velocity (short period bursts). What if one wants to increase the radius of a circular orbit with a very small constant thrust? I assume the thrust should be applied tangentially in the direction of travel, but what would be the...

If one writes down the Newton's equations of motion for the Earth, the forces that act on the Earth are the gravitational forces exerted by all other massive bodies, such as the Sun, the Moon, the planets etc. The largest of these forces is that of the Sun: keeping into account only the Sun's...